Your numbers are off though. Firstly it's ~40ms up to the bird if it's right above you, then 40 down to the base station if it is next door to your house. If it's on the other side of the world and has to travel around the whole mesh, add a hundred ms at best. Then from the base station to the destination - which could be anywhere in the world, and back, then back up to the bird, then back down to you.
It's not going to be 40ms, probably not even 400ms, and there is no way it will be competitive with mobile 5G.
It might not even be competitive with the geostationary birds for accessing nearby hosts. 22k miles is ~120ms, so 240ms round trip - because the base station is generally pretty nearby. Say ~20ms both ways for in-country ping and you're looking at 520ms -ish total, which is reasonably consistent with my experience using it from the Solomon Islands.
Huawei's saying 1ms to the tower for 5G!