I had absolutely no problems updating Debian to 13 from 11 to 12 to 13 one after the other. I also had no problems upgrading between Debian versions when I ran it as my main driver from the Potato release up until Ubuntu came out. Conversely, when I used Ubuntu from its original Warty release to around 2012 or so I had issues on literally every single version upgrade. Most relatively minor, but more than a couple requiring full reinstalls.
I would bet money that the vast majority of those having problems upgrading Debian are on “FrankenDebian” systems. Not all, but I am confident the majority are.
I had absolutely no problems updating Debian to 13 from 11 to 12 to 13 one after the other. I also had no problems upgrading between Debian versions when I ran it as my main driver from the Potato release up until Ubuntu came out. Conversely, when I used Ubuntu from its original Warty release to around 2012 or so I had issues on literally every single version upgrade. Most relatively minor, but more than a couple requiring full reinstalls.
I would bet money that the vast majority of those having problems upgrading Debian are on “FrankenDebian” systems. Not all, but I am confident the majority are.