As someone who used to work on embedded hardware day-in and day-out (though it's been close to a decade since I've worked in that sector), I can assure you that really is the case, if you consider a more long-term view.

Every time I look at one of the alternatives to the RPi, I just don't have confidence in the tools and community. I don't want to have to do what I used to do when I worked on embedded hardware for a living. It was fiddly and annoying (though it did have its truimphs), and mainly only tolerable because I was getting paid to do it.

I want a stable, working, well-supported, upstreamed platform that I can build on without too much fuss, and also feel confident that I can keep upgrading the OS and kernel to whatever is the latest, for the next 5-10 years, even if the company behind it disappears.

I play with this stuff in my spare time, and fighting with a chip vendor's nearly-always-shitty BSP is not what I consider a good use of my time. You (being someone who currently works on this stuff day-in and day-out) are in a very unique position that you can leverage to make it easy and productive for you to build on random hardware platforms, especially the ones that aren't even mainstream RPi competitors; most people posting here about this sort of thing are... not in that position.