I have returned several times over the years about how hard it is to understand Shakespeare, particularly in performance. John McWhorter, who I listen to, has come back to it a few times as well, as you will see at my link. I am pulling this out from one of his about five years ago plus some additions of my own.
To begin with it is poetry, which we are not only unused to but is often committed to using indirect phrases or allusions to other knowledge we might not share with the original audience. We have similar difficulties with Chaucer or Beowulf. There are prose works in those earlier versions of English we understand more readily. Next, it is in Early Modern English, only debateably our language. Even when we think we know words, simple words, we sometimes get them wrong. In 1600, "let" could mean forbid, which is an opposite of how we understand the word now. It can throw you off for a whole section trying to work that out. Directors and actors often downplay the parts they know the audience is going to get confused by, hammering home the parts they think will be easier. In this monologue of Edmund's in King Lear, the chimes are rung on "base," "bastard," "illegitimate," and by tone conveying that his self-descriptions using I, me, my are Edmund stating how he is just as worthy. It helps. We miss that "generous" actually means noble, and have no clue what nations could possibly be curious about (try "silly customs" there), but we get the general sense. And then when we get to something like the part I italicised, we have great joy that we understand it! The myth* that Appalachian English is closer to Elizabethan still persists, yet what do we think the average Appalachian lad would make of the phrase "twelve or fourteen moonshines?" If we doubled back to explain it he would readily get it, but he would have to fight against his initial impression.
So modern audiences don't get it, even when they are educated and pretend to. I have to guess that Shakespeare would disapprove of our clinging to his phrasing at the expense of people getting the story. ("Give me that quill, you ignorant fools!")
Thou, Nature, art my goddess; to thy law
My services are bound. Wherefore should I
Stand in the plague of custom, and permit
The curiosity of nations to deprive me?
For that I am some twelve or fourteen moonshines
Lag of a brother? Why bastard? Wherefore base?
When my dimensions are as well compact,
My mind as generous, and my shape as true
As honest madam’s issue? Why brand they us
With base? With baseness, bastardy? Base, base?
Who, in the lusty stealth of nature, take
More composition and fierce quality
Than doth, within a dull, stale, tired bed,
Go to th’ creating a whole tribe of fops
Got ‘tween asleep and wake? Well then,
Legitimate Edgar, I must have your land.
Our father’s love is to the bastard Edmund
As to th’ legitimate. Fine word-,’legitimate’!
Well, my legitimate, if this letter speed
And my invention thrive, Edmund the base
Shall top the legitimate. I grow, I prosper:
Now gods, stand up for bastards!
And there's this soliloquy of Macbeth pondering whether he should kill King Duncan, which begins with a famous phrase. I recall a Sports Illustrated article from the 80s lauding some college basketball coach who considered himself an educator as well as a coach using the first line and a half during a time-out near the end of the game and being proud that his team, mostly urban blacks understood what he was getting at when he said the words. "Yeah, we get it, coach. Get the ball in to the big man." Well, fine, it's a good story and all that, but that's about the only easily understandable part. And this is, remember, one of the most famous soliloquy's, the sort of thing that and audience would have to have some clue about to understand the play. In writing, you can get single words in the margin that trammel means "tied," and surcease means "death," but you don't get that in the seats.
If it were done when ’tis done, then ’twere well
It were done quickly: if the assassination
Could trammel up the consequence, and catch,
With his surcease, success; that but this blow
Might be the be-all and the end-all here,
But here, upon this bank and shoal of time,
We’d jump the life to come. But in these cases
We still have judgment here; that we but teach
Bloody instructions, which, being taught, return
To plague the inventor: this even-handed justice
Commends th’ ingredience of our poison’d chalice
To our own lips. He’s here in double trust;
First, as I am his kinsman and his subject,
Strong both against the deed; then, as his host,
Who should against his murderer shut the door,
Not bear the knife myself. Besides, this Duncan
Hath borne his faculties so meek, hath been
So clear in his great office, that his virtues
Will plead like angels, trumpet-tongued, against
The deep damnation of his taking-off;
And pity, like a naked new-born babe,
Striding the blast, or heaven’s cherubim, horsed
Upon the sightless couriers of the air,
Shall blow the horrid deed in every eye,
That tears shall drown the wind. I have no spur
To prick the sides of my intent, but only
Vaulting ambition, which o’erleaps itself
And falls on th’ other.
Sometimes giving just a word here or there can give you more of the sense.
"That but this blow might be the be-all and end all here" is clearer just by subbing in "that if this blow..." You slide past whatever the jumping is about in the life to come with an idea that it's something about risking judgement in the afterlife, which is confirmed by the next lines. But commend, commend, what's that about? If we had the word "returns" in there we could hold it better. "Justice returns the ingredients of our poisoned chalice." And so on. We get the idea that Duncan is virtuous, but knowing that "faculties" means authority would give us a head start.
I did find an explanation, if you want to work your way through it.
People object to any change in Shakespeare's words (even though there are sometimes multiple manuscript variants and we went from 1650-1850 with practically every production altering what it liked, even putting in happy endings. This went on until the 20th C) as if they were scripture. Perhaps having no scriptures they believe in, they need to find some words to revere in similar fashion. When translating Shakespeare is mentioned, there is an immediate defensiveness of sneering at the worst examples they have ever heard of: "What up, Romeo?" or the like. But alterations here and there - a word or two every few lines - would give audiences a fighting chance of understanding what is really happening, not just getting the general thrust of the plot and character traits plus recognising some phrases.
I have also read the suggestion that a dozen or so words should be part of core curriculum with the specific intent of being used to understand Shakespeare and other older material: nailing down what the formal and informal thou's and thee's and you's are, teaching that "science" and "wit" meant any knowledge, not chemistry or humor, and of course, getting it straight right off the bat that "wherefore" doesn't mean "where," but "why."
*Have I ever explained why that persists? I should.