I've had a similar experience. I would love to stop using Windows but I have found that ProtonDB wildly exagerrates the compatibility of games. I had game breaking issues with 50% or more of "gold" rated titles and even some with a "platinum" rating.
ProtonDB tells you that someone, somewhere at some point managed to get it working. It doesn't directly help you, but knowing it can be done can be an incentive to experiment instead of giving up.
That's unfortunately not unexpected. "Linux Desktop" is a ludicrously diverse not-platform for which Valve already has to bring its own runtime of basic libraries along just to ensure some minimum level of compatibility even for native Linux games.
