Recently I even got suspend to ram working on my rk3399 powered pinebook pro, which was one of the few items I had not been able to get working with a mainline stack.
Hardware video decoding does require a recent kernel and gstreamer, but again it is fairly well documented and entirely mainline.
Don't the RPI boards require blobs to boot the GPU, which boots the rest of the board? And hardware video decoding requires paying extra and using a proprietary blob?
That said, this device (and the RPi 400) seem really wacky to me and I doubt I would ever buy one. I would not want to tell my grandparents "sorry printer does not work because arm" and the keyboard is way too sucky for me. Also no track point? That would be great for this form factor.