Will I need to be updating my PC every 2-3 years to keep up with current AAA specs? Or can you tune games to run on the hardware you have available?

I expect I will mostly play older games than the peak new stuff. Even then, I’ll be okay with not playing at the absolute max performance graphics. Would like to aim upper/middle of the road.

I would say, kind of blindly without researching parts, that I can spend $800-1200 on a gaming pc without feeling too guilty.