ubuntu is just the apple of linux world
ubuntu is everything working out of the box
ubuntu is made with the foundation of an ex businessman whom dislikes win/mac
ubuntu is a linux among hundreds of linux distros
openbsd is a rock-solid safe regarding security
everything is handlymade to get a taylored-made computer.
if I had to compare, ubnutu is a bit like a high rank standing appartment in a big city where openbsd is a very nice home handly made to answer to all your choices and decision, whom might not be delivered with several defaults when you receive the keys ;)
Ubuntu was my first choice to make the jump from Windows. My current daily driver is Pop!OS, which seems equally user friendly to Ubuntu with minor differences in the details of usage.
I've been using Linux since RedHat 5.x "pocketbooks" with CDs were available at newsagencies (late nineties?), so I'm not scared of the prospect of having some fiddling to do in setting up OpenBSD. The main concern would be the availability of compatible apps that I use regularly.