Yeah, but starlink can just cycle in newer generation satellites with tighter beams as well, could they not? Is there a technical reason I'm not aware of that they can't? Would Dishys even need to be changed?

Kuiper needs Blue Origin to get cost competitive with SpaceX, which doesn't look likely because a) they don't even have commercial operations and b) uhoh, here comes Starship.

Sure SpaceX might launch Kuiper satellites ... at a premium over Starlink.