If you think about it
fish swim in about three basic speeds: fast (like swordfish), slow (like sea horses) or they are bottom dwellers, sit-and-wait predators (like frogfish). We know some bottom dwellers eventually grew legs and became tetrapods. I hope you find this interesting as I apply colors according to fish speeds in this subset of the large reptile tree (LRT, 1548 taxa, Fig. 1), seeking phylogenetic patterns, if they exist.
Not sure what else can be said here.
Evolution can take a bottom dweller and turn it into an open water speedster, but usually not the other way. The genus Seriola is an exception giving rise to mudskippers and frogfish. We are descendants of bottom dwellers. So are birds, bats and pterosaurs.
If any of the above generic names don’t ring a bell,
type them into the keyword search box.