I'm thinking about just forgetting about 6000/3000 series and mothballing by PC until the 4000 series and sell the Series X around then. My concern is a 3700X CPU and 3200MHz ram (32GB) coming into 2022. Hoping it would not be a bottleneck at 4k by then.
The Ryzen 7 3700X will be fine for a few years IMHO,especially if you are not buying £1000+ GPUs for RT:
https://www.youtube.com/watch?v=AlfwXqODqp4&t=1455s
The fact is every generation there is a "better" CPU coming out,so if you measurebate every year on CPU graphs,you will never keep a CPU for longer than a year or so. Hardware forums are full of people who eternally need to justify upgrading,and I tend to be wary of reading too much into things. You can always tweak settings,etc and stuff like FreeSync/Gsync help a lot if you monitor supports it.
The games which I found which are very CPU limited at higher resolutions all are based on older engines design with Intel CPUs in mind,so are latency dependent and push one or two cores a lot. CPUs like SKL-X had issues with the same games,but consumer Skylake did not. Even the so called modern CPU limited games,also tend to be very GPU limited too,and realistically in most cases,as a person who does not upgrade CPUs that much,I found 90% of the time I have been GPU limited. I remember being on SB/IB for years,and yes you could force a CPU limited scenario using lower resolution testing,but in the realworld you still need a fast enough GPU to see it at higher resolutions. I had an IB Xeon E3 1230 V2,and went from initially an HD5850 1GB to finally a GTX1080,and only with the latter(which was several times faster),did I start to see some CPU issues at qHD.
ATM many games are intergenerational so are really only taxing a few threads heavily,so these very same games you can see a Ryzen 5 5600X/Core i5 10600K matching their 8~12 core versions. You see this with CB2077 which runs better on Intel CPUs rather than Zen3.
Once games more to the next generation consoles,literally all the console based dev kits will be based around Zen2 - this is the CPU in the PS5 and XBox Series X,in a lower clocked and L3 cache limited form(similar to the CPU part of the Zen2 APUs). Games on the next generational consoles will have to take into account the dual CCX design,which games currently really don't need to. If they don't the consoles will hit more CPU issues.
Also WRT to RT,you are still massively limited by the GPU hardware,especially the amount of RT cores,memory bandwidth and VRAM. This is why with my RTX3060TI,I see performance at 1080p in CB2077 is still significantly higher than at qHD when you switch on all the RTX effects.
I am also seeing double the performance at qHD in some of the most CPU and GPU demanding areas of the game with the previous non-RT settings(lots of NPCs,and lighting effects),when compared with my GTX1080. FPS went from around 30FPS to around 50~55FPS.
This is despite there being "faster CPUs" for the game.
So personally I think you are OK for the time-being,unless you get a really cheap deal on a Zen3 CPU. 2023,will have new generation DDR5 platforms out with even more performance,so everyone saying to get Zen3,will then say Zen3 is too slow,and then you need a Zen4,etc.
You can then carry over your RTX3080. However,if you don't really use the PC for gaming,and use other platforms more,than yes it might make sense to sell it off when the parts have value and use those systems.
