PUBG is only optimized for new systems?

I always complained about how badly optimized PUBG was. I always had some problems with the game. Lags, crashes, bugs, fps drops.

I played for a long time on i5 8600k, 1070ti and 16gb ddr4 3200CL16 and then from one day to the next the game became unplayable. No fix, drivers, settings, nothing helped.

With a new PC i5 14600kf, 4070 super, 32gb ddr5 6400CL32 all problems suddenly disappeared. The game is stable, it doesn't crash, I have no bugs, launcher problems, fps drops or anything like that. Stable 240 fps (locked to 236 fps because of monitor refresh rate).

I don't consider this PC to be a rocket, it's more like a middle class PC for todays standards.

I don't recall any major graphical or other update recently that would have made the game fundamentally HW-havy.

I'm thinking there was some "silent" patch that prepared the game for a possible switch to a new engine or something like that and they didn't optimize it for older systems anymore.

What is your experience and what do you play on?