I used to do that until I realized how painless Debian upgrades are. When I went from 10 to 11 I was prepared for endless problems. And… after the reboot everything worked. It was so weird. After Ubuntu upgrades there was always something broken (which I have to admit did improve my knowledge in many ways, esp with how often I was fixing things purely from a console due to Xorg not loading…)

Or testing if you’re adventurous and don’t mind your software changing before the inevitable package freeze.