A while back I decided to have a go at using a Raspberry Pi 4 as my primary desktop machine. I went with Ubuntu for the OS which was a bit of a slog at first, but these days it is pretty well supported, mostly. I currently have three other Raspberry Pis in the house, two Raspberry Pi Zeros being used for network monitoring and as a lawn sprinkler controller and a Raspberry Pi 4 on the downstairs TV for streaming.
I didn’t have much choice and stuck with the Raspberry Pi OS for the Zeroes, since I Ubntu wasn’t available. It was only 32-bit bit for the simple embedded applications it was enough. I also had a Zero side project to display images on a TV, a bit like those LCD photo frames. A Zero was good enough for that sort of thing and I used Raspberry Pi OS again.
Ubuntu on the TV became a bit of a problem. The GPU support is lacking and you really need to GPU to watch video. Every time Ubuntu would update, it would silently clobber my GPU support. Last night I decided to dump Ubuntu and go with Raspberry Pi OS. It took no time at all to install and configure and the resulting video was so clean my wife even commented on it.
I suppose for now I will stick with Ubuntu on the desktop and deal with the spotty support, but I think all of my future Pi projects will be using Raspberry Pi OS.