Buying gaming PC to play the most demanding games (AAA title) but however investment requires to have savings for month to month or if you have good source income that would be easier.
Since AMD announced their Zen 3 would be the last AM4 socket cpu, that means Zen 4 would be AM5 socket cpu along with DDR5. Besides it's still possible to game on DDR4 and Zen 2 for now.
If you have bought and built gaming pc from 2019 than it's great idea to wait instead of just buying currently released cpu/gpu on the market. Besides you can save up your money for the next-gen release in 2022. 3 year warranty absolutely is enough for next release. Building whole new PC would cost you some dearly if you dedicate resources for a great build.