I’ve had a steam deck for a few months, and have tried dozens of games already. Both pirated and owned on steam.
If it’s a pirated game or a game that’s not available on steam, I just add the .exe as a non steam game and launch it with the latest GE-Proton version that I’ve installed with ProtonUpqt. It literally always works flawlessly.
Lutris is much more complicated than this, I know cause I’ve used it on desktop linux in the past.
So why is Lutris so recommended to people here, especially to beginners?
It’s because Lutris makes it a lot easier to install games that *don’t* include all their dependencies in a tidy format.
The method you use works great for many games, but many more need you to track down old VC++ redistributables and all that other stuff, then install them manually. Community launchers like Heroic and Lutris sidestep that a lot of times.