I distro-hopped a bit, but if I’m remembering correctly I settled on Mobian with Phosh. I don’t like desktop Gnome but Phosh is nice IMO. It’s also smooth if a bit slow due to the age of the hardware. It’s not a stuttery slowness. Plasma mobile seems a bit further behind in that regard.

This was an original PinePhone, not the Pro, so maybe the community simply had more time to mature the software (there’s not exactly many developers). I still have it but the screen is smashed and I need to replace it.

Note: this was over a year ago, things have most likely changed, maybe Plasma mobile is where Phosh is now.