Just a thought - many of the greatest performances by our leading actors have been read from the page.
The definitive example would be Dylan Thomas' 'Under Milk Wood', starring Richard Burton.
I'm referring , of course, to the art of the radio drama (and comedy, come to that) which is read from a script and can lead to undeniably rich and rewarding, sometimes award-winning, performances.
In the case of some classic radio comedy - eg The Goon Show - this was achieved without a great deal of rehearsal or production.
It's nice to see singers doing it all from memory, but I don't personally think the end of civilisation is upon us if a crib sheet is used from time to time.