@Nullo I don’t know where you get this idea that plays are made to performed as written. I was at a reading of about eight short plays Sunday and we were told, quite specifically to talk to the actors and playwrights after because the plays are being changed all the time.
Shakespeare, in particular, is changed all the time. No one, as far as I can tell, seems to think they are required to play it as written. Most productions seem to pride themselves on taking new approaches to the material. If anything, the written play is a guide, if even that. Maybe just a signpost.
Theater is a living thing and the actors are always improvising new lines and productions are constantly changing to make them work better. There is, functionally, no final version of a play. Ever. I’m afraid I find myself in agreement with @6rant6 on this one.
The idea that you should remain faithful to the text, as written, is just that: an idea. Some people do it. But I would hazard a guess that that is probably the least common form of performance. Most productions change the play. That’s the whole point of producing it. You really have to because every theater is different and you have different talent for each production. There is really no choice but to change things. Besides which, you have no idea what the original looked like, anyway.