They could increase A LOT players agency/creativity if custom mechanics weren't so overpowered.
If D&D is about player's agency and creativity, let us also only play with D&D rules and spells and class abilities rather than impose us a good way of playing.
I'm 100% fine with their will to add more things and even silly things I won't use (like throwing boots or ennemies)... But please let me play this incredible game how I want to play it...
A better balance between custom rules and RAW mechanics is the only solution so players can CHOOSE and use THEIR creativity rather than yours.
Baldur's Gate II had several difficulty settings, with one being core D&D. It makes the game more enjoyable for players for different reasons. They included harder modes and the easier versions were often to fix the fact that it's a video game adaptation of a pen & paper game. I'm sure something like that will happen here.