I bought 100 GB of DDR4, 3 GB DDR1, and 24 GB DDR2 in August and September. I probably won't need to buy more RAM fur the rest of the decade.
You'll assuredly be able to salvage low-grade modules from laptops and Dell desktops furever though. I'd only be concerned if I had made the move over to DDR5.
Regardless, I'm relaxing my desktop's RAM timings. Not worth the risk atm...