You could always resell the board if you want to replace your chip after a year, or you could be like most and just keep the setup for 5+ years because it is fast enough. You would want to replace a board for either chip vendor after 5+ years either way.
I imagine someone who wants the latest and greatest every other year would also want the latest and greatest motherboard.
Have AMD boards caught up yet with TB4 and cudimm support on the low end yet or will one have to buy a new motherboard for that?
Yes, I haven't upgraded a CPU on a motherboard, since... thinking... Intel 80486 to a faster 80486? In the early 1990s?
Do people still do that?
The upgrades I've made in the last 20 years:
1. Replace HDDs with SSDs
2. Replace HDDs and SSDs with bigger ones.
3. On very rare occasions I've updated video graphics cards - but not in the last 10 years.
4. I updated a few PCs with more primary memory.
5. Replaced a lot of batteries in notebook PCs.
Upgrading a CPU just never seems to be something that seemed worth doing.