That’s a kinda bad statistic to use. Most games don’t get lots of attention. And since only a fraction of players use Linux even more games don’t get played by Linux players. Those who play also have to make reports on proton, and not everyone does that.

If you really want to know about Linux compatibility, search for the stats of the protondb database. Only 13% are below silver( they either have a bronze rating or are borked).

where did you get this stat? Do you mean “working” or “verified”? VERY FEW games in my steam library don’t work out of the box. I forget to check when I buy them, they work that consistently

Cite your sources.