Well, yes: historical importance doesn't always coincide with artistic excellence.
Gammer Gurton's Needle is an important play. So is Kyd's Spanish Tragedy (the template for Hamlet.) I wouldn't pay good money to see either of them.
I might pay good money to see Middleton's A Game of Chess- the most popular and controversial play of the Jacobean period- so popular and controversial it got the theatres closed down- but I suspect I would be fidgeting in the stalls.
John Osborne changed the English theatre, but he wasn't a great dramatist. The only thing of his that I've sat through is his supposed "masterpiece" the Entertainer and you can see better crafted work on TV any night of the week.