I've found games running in Proton to provide better long-term compatibility than many native games. Despite Steam providing a stable runtime for native games, I have a few titles from their first major Linux push back in the '10s that are now crash-happy or exhibit substantial performance problems, but work perfectly fine when I use the Windows version with Proton.
Telling people not to even think about using their favorite piece of software is a good way to make sure they don't consider switching. A lot of popular Windows apps run perfectly fine in WINE. I've been using foobar2000 in it for a decade at this point, and have yet to find a native alternative that gives me the same feature set. So why shouldn't I keep running it?
> provide better long-term compatibility than many native games
This is one of the big, but less obvious, benefits to Wine/Proton. Games with native Linux builds run into all kinds of distro-specific issues that you don't really get on Windows. It's an issue for new games and an even worse issue for older games that aren't being updated anymore. Just look at Steam on macOS to see how big of an issue this is - so many games are not compatible on the latest Macs because they were built for x86 (32-bit).