You don’t have to tell me. But while it would be slightly annoying, you could just use service X one month and service Y another. (In reality people in general probably rarely bother switching around between Netflix and competitors.)
Still, my expensive copy Shadow of the Tomb Raider + season pass actually doesn’t compare too badly to a hypothetical subscription. I played it for 1-2 months, and then every month there’s a new DLC, although I’m currently one or two behind. It seems reasonable to assume similar models would exist on streaming services to tie you in, so then you’re actually looking at € 80-100 to play Shadow of the Tomb Raider the way I’m doing (i.e., spread out over about 8 months in total), which definitely exceeds what I paid for it.
NB Unlike GOG, I basically consider anything on Steam a long-time rental. Basically a better version of Google Stadia but with many of the same fundamental problems.
 Expensive for my buying habits, anyway.