sounds like maybe your power supply might be dying or your system is pulling more than that psu can handle. mine recently blew a capacitor with a loud bang and magic electronics smoke after a few months of odd problems with shutting down in the middle of an intensive game. i think the fan died about a year ago bc my temps had been higher than they used to and after it popped the side of the case by the psu was very warm. i came to find that my gpu upgrade pushed my power draw to 450w when my psu was only rated for 530w and not 750w like i thought i remembered. makes sense it was pushed to it’s limit. maybe recheck your power requirements with an online psu calc and compare to your psu rating. and also look to see if its fan is still running and not clogged up with dust.
further, heroic games launcher isn’t just for epic and gog games, you can install any exe. i use it for the ea games launcher because the lutris script was broken at the time. and in the wine manager in hgl settings you can choose either wine-ge latest or proton-ge latest (or whatever number version) as your default layer, which you can also change per game/app if you have trouble.
edit: and also you can set it to add to steam so you can still just use steam as your main launcher, for example on steam deck or using a media center rig in big picture mode.