Wouldn’t that make Scrabble only harder and more annoying to play? With that limitation you’ll get situations where you play a perfectly valid word, but it gets rejected because it’s not in the list of approved words. To get good at that version of the game, you’ll have to study the Scrabble word list instead of the dictionary.
With Wordle the limitation is only put on the words the game generates as answers. You can use obscure words to guess, they just won’t be the answer.
this is already the case with scrabble; there is a strictly defined scrabble word list that determines whether a word is acceptable or not, and it often leaves out words that you might find in some other dictionary that is not the official scrabble one (collins for most of the world, or a custom dictionary for american scrabble)
Ah ok. Shows what I know about Scrabble.