How would it change the game play style if players can see each other's racks in Scrabble?
It would make gameplay more frustrating
There is very little to gain, and a lot to lose from this tweak.

Because players have more information available, it will take longer to decide what the optimal play is.

Because other players can see what you have, they are more likely to make moves that will block your best possible play.


Rather than encouraging strategic play, open information would instead encourage tactical play - you've added more information about what your opponents have right now, while adding comparatively little information about what will happen in the future.