No real answer to this question, particularly forward looking. 6080 doesn't even have a codename yet, so likely 2.5 years or more away.
Faster components allow other components to perform better up until they can't. It depends on the workload, game settings, etc.
'Special' charts would be GPU benchmarks using multiple CPUs. These are somewhat common, though most GPU benchmarks are done with the fastest CPU available to avoid any limitations, basically show each GPU with the same host system for a direct comparison.
People often use the term bottleneck when referring to CPUs and GPUs. It can be correct, but is often mis-used. The common mistake is that putting a faster component in amongst slower components will cause a bottleneck. If you look at it from a perspective of performance, it will almost always increase somewhere. What they mean is that you could get more performance if the other components were faster.
Common example, like you are looking at. Older CPU, new GPU. Your CPU sets the maximum FPS possible, because that is where the game engine runs. It directs the GPU to create the frames. So while you might be stuck at 85 FPS or something, you could now increase game settings, resolution, textures, etc and enjoy a better looking experience at 85 FPS. Replace the CPU and you could now get 105 FPS, but maybe the GPU can't do that at your current settings. So you would have to reduce the game settings and then achieve 105 FPS. Where the limitation is moves around depending on what you are doing, essentially.
Basically, good to say that the best systems have a balance between the components. Nothing wrong with putting new hardware into an old system. It will perform as well as it can, and if you make additional changes, you can expect some improvement.
Now, there are extremes of course. You could take 1st gen i7-920 and drop an RTX 5080 into it. It would work, but that CPU would be a serious limitation in contemporary games.