What are the major thing that should change in a freelanzing sites according to your view and experience ?

The $5 projects and scammy bullshit clients.

Just my 2c 🤓

The grammar and writing skills, I presume.
Just kidding.
I have seldomly used freelancing sites and the only thing that comes to my mind is that it can be somewhat difficult to present your abilities to a future client.
Often clients just choose the cheapest dude and that's it.
But that's just my opinion from the handful of projects I applied for or got.