I picked up a radxa zero last year and have been quite enjoying it. the hardware is better than a pi zero but costs less. same with a lot of other SBCs
but raspberry pi has a lot of inertia behind it, a lot of software and hardware support. people will keep using them, just like they keep using Ubuntu, even though it's a soulless corporate husk of what it one was
As long as I'm not locked into using their OS on their hardware I'll still be interested. I have a 3,4&5 doing various tasks around my house and enjoy the little boards.