I didn’t see a reason to upgrade and I feel I am their audience here, I own the last one.
https://everymac.com/ultimate-mac-lookup/?search_keywords=A1...
But it's got a lot of miles on it. No complaints.
The last MacBook with upgradeable RAM was the non-retina 2012 Pro.
But that's quite the price bump. The M1 Ultra studio handles my workload pretty well, so I'll maybe save up my pennies for the Vision Pro.