rumour is that AM5 socket will continue until zen 7
Thanks for the correction.
If you upgrade so infrequently, then even with extreme longevity of AMD platform, you will rarely get an opportunity to do CPU only upgrade. So, it really doesn't need to be a concern for you.
I tend to have a similar strategy, waiting for 2x CPU performance to upgrade, and I just happened to get Zen 4 (7800x3d), and in my case, CPU only upgrade to Zen 6 (or even Zen 7) will be quite an attractive proposition.
... and I think that the frequency of CPU generations (as well as the relative performance increase from one generation to another) is ALSO likely to slow down.
Still, given the fact that the current so given the current socket will exist for another 2 generations (likely out to 2030), I still wouldn't likely upgrade unless I had a failure; however, at least now I wouldn't feel bad about it.
I assembled my current rig with a B450 and a 3200g processor that I later upgraded with a 5600g and a RAM upgrade to DDR4 3600 (32Gb) from the original DDR3000 (16Gb).
This is why I have been building AMD machines since the late 80's. They support a platform for a long time. Intel? What a joke.
I built my current system in 2018 I believe, so it's doing pretty darned good as far as ROI goes (it's also been upgraded to Windows 11).
How many people have laptops that old?