Re: a stern warning not to try to upgrade
[Author here]
> Yeah, they have far fewer developers than Debian or Ubuntu, etc,
No, not really. Raspberry Pi OS *is* Debian.
As it happens, last night I spent 45 min chatting with David Jones who looks after the Raspi builds of Ubuntu, and I found out some very interesting stuff, but I'll have to get the OK to publish it.
But the RPiOS team is the entire Debian team _plus_ the PiOS developers _as well_. You have the arithmetic backwards: it has _more_ developers.
> they have never managed (or bothered?) to get 'upgrade in place' working
Again, no, and in the article I linked to not one but two ways to do it.
The real point is that this is a £35 computer and it's not worth spending hours of your time carefully upgrading it when a reflash is much quicker and easier and lets you spend the time on making something with it, or learning a new skill with it.
It doesn't have much space. Its nonvolatile storage is slow. Therefore, the upgrade process will also be slow. It might fail because you run out of room.
The Pi Foundation doesn't want to have to help people who tried it and it failed. So, they tell you not to.
But it's Linux. You are free to ignore that and do it anyway if you wish... but you're on your own if you do.
It is, as others have pointed out above, the same old story, but at least with Linux if you don't want to follow the rules you are free not to.
If Microsoft tells you "thou canst not upgrade 32-bit Windows to 64-bit" then that is it: you can't.
If the Pi crew tell you that you can't, you can do it anyway, and I provided instructions on how to.