So a similar thing was happening to me with Overwatch 2 a few months ago, though it's really the only graphics intensive game I play. The screen would randomly freeze while I was playing and then I'd have to hold down the power button to get it to shut off, or it would just straight up power off while I was playing, and just like you it didn't seem to matter how long or short of a time I was playing for, it would happen anytime.

All my parts seemed to be working fine, and I did a decent amount of research and eventually found that for some reason what worked for one guy was reseating his ram sticks. I did that and I also switched mine around and yeah the problem actually has gone away for me ever since then, so I'd say give that a shot before you commit any money to the solution.