Most gaming rigs built 8 years ago might not have a motherboard that could even capitalize on modern SSD tech. My PC is rocking an RX480 that's nearing about 8 years of use, but the PC was actually built several years before that. As a result my motherboard doesn't even have an m2 slot or anything more than a SATA3 interface for any type of storage device.
Sure a SATA3 SSD is considerably faster than an HDD, but by no means is that going to improve gaming performance in a truly noticeable or meaningful way. I don't have the means to upgrade my PC any time soon, but even with the SSD I have installed I can't run most modern games even on lower settings. Act 1 of Baldur's Gate 3 chugged along, but as soon as I hit Act 2 the game is unplayable.
I'd argue that perhaps for most ppl keeping an 8+ year old GPU going might be fine if you aren't playing modern games, but don't tell me you can run a new AAA game even on lower settings without a hitch.