Regarding mainline: No, not really - but I think we're in for a decent future with much-expanded mainline support.

The difference between the bastardized stuff from the Pi Foundation and everyone else's is that the former has enough momentum behind it that it's safe to assume it doesn't simply wither away, which makes enough difference for me not to experiment with others that almost certainly will. (I have a small drawer full of SBCs without any remaining software support at home from a past where I did not live/buy by that standard.)