It was nice knowing Raspberry Pi while they lasted. Going to suck losing something that has changed the homegrown embedded system hobby forever.
This is the key point for alternatives. None seem to have the community and support (docs, s/w quality etc) that is remotely close to that of the Raspberry Pi.
They have more features though, like extra Ethernet, PCIe brackets and M2 slots on the board
Those features don’t mean shit if you can’t use a modern OS after a couple of years.
Why could you not run a modern OS after a couple of years? Those SBC manufacturers did not invent an entirely new processor architecture for their computers, you can just generically compile the kernel (plus maybe some slight device tree work).