I thought it was explained. Local gravity is moving things together much faster than general expansion is moving them apart. At super super long distances, grav

I thought it was explained. Local gravity is moving things together much faster than general expansion is moving them apart. At super super long distances, gravity is weaker than expansion, so something very far is disappearing while something nearby may be collapsing. However, that questions a different future I’ve seen in popular science talks: That the future becomes dark because of expansion. That makes less sense to me now, since it would seem that a merged set of galaxies would keep plenty of local stars in the skies. Assuming that stars are born as fast as they die (but I don’t recall seeing an answer to the ratio of star births vs star deaths at a local level).