Zen 2 to Zen 3 seems like it was the biggest jump yet in terms of gaming for Ryzen gens. I've got a 3900X which is fine for what I do for now, but I'm very interested to see how Zen 4 or even Zen 5 go down in the years from now. In the past, I've often kept the same machine for ~5 years, but if the level of improvement gets close to what we've seen with Zen 2 and Zen 3 when Zen 4 or 5 roll around I think i'll be pretty tempted to upgrade every ~3 years perhaps. Currently the market is kinda awful price-wise but there are also some great hardware releases. If Zen 4 blows me away I might bite the bullet then rather than wait it out for Zen 5.