How many competitive ARM SoC vendors that have good software higiene out there?

Who says I have to buy an ARM SoC. I can always just check out and keep using second hand devices. Or something from Intel, if I need more power.

And to answer your question, two come to mind, NXP and Amlogic.

Are we still talking about Pine64?

As for blobs without source, the same happens with x86 all the time. If you really want a fully deblobbed computer, you can try one of the POWER boxes from Raptor.