Slight tangent - even though the MBP has been struggling to handle my dev work (partly because the codebase I'm working on has grown significantly in the last two years) I won't be upgrading. Work bought me a MacStudio (M2 Max), which mainly runs headlessly on my desk (also running Homebridge and plugged into my big speakers for AirPlay). This means I'm keeping the MBP as my portable machine (using VSCode's remote extensions and/or CodeServer to do dev work from wherever). I also have a late-2015 27" iMac at the office (with OpenCore Legacy Patcher so it can run whatever the latest macOS is called nowadays). This also works perfectly well now all the hard stuff is done on the MacStudio - and the screen is still lovely. (My previous 27" iMac was in active service for 10 years, although it was almost unusable towards the end).
Another tangent - I bet that's why they're not doing the larger "pro" iMacs. If it weren't for VSCode Remote Extensions and OCLP, I would have ended up with a beautiful monitor that was essentially useless (as was my original 27" iMac). People who need that extra power should probably avoid all-in-ones and I won't be getting one again.
But for most people, who tend to have a single machine, a comparison to the 3 year old equivalent seems pretty fair to me.