Consider the fact that we, humans, descended, as monkeys, from the trees. WE EVOLVED IN TREES. Perhaps life evolved as it climbed from the ‘primordial swamp’ into the roots and up the tree…
In my humble opinion, not all amphibious creatures are evolutionarily successful, consider reptiles such as a crocodile, they are considered to be in an earlier state of evolution (i think they are similar to their dinosaur antecedents). And real Amphibians habitat is mostly around trees, the Green Tree Frog… I cannot perceive how crawling out of the water and up the beach would offer diverse opportunities for successful and transitional evolution. I love turtles and crocodiles, but they exemplify my argument by being fairly
It makes much more sense if we consider the tree as integral to our evolution. Even in the epoch(s) of the Dinosaurs, the understanding that birds are the current evolutionary relative of dinosaurs, points to the idea that, trees were integral to their evolution as well...
WE EVOLVED IN TREES. If life started in the oceans it makes more sense that mangroves and other intertidal trees became the first habitats for life and the evolution of such life proceeded upwards from there.