Proton DB says that 89% of the top 1000 games, 89% of the top 100 and 6 of the top 10 games on steam are rated Silver or above (a 7th is rated Bronze and 3 are broken).

AreWeAntiCheat yet says:

161 games are Supported (42%)

46 games are Running (12%)

3 are planning to support Linux (1%)

147 are currently Broken (38%)

28 (only) are explicitly Denied (7%)

So, many don't but, also, many do. Not everything, not nothing.