Why did the tiktaalik move to land?
Sure, there were no predators there, but also no food either. It wouldn't get very far thanks to its fins, it was a completely unnavigatable environment.
There was nothing for it to do after beaching itself other than drying out under the sun and suffocating unless it went back.

So... why'd he do it? And considering the way natural selection works, can you imagine literal tens of thousands of years if not even more, of endless tiktaaliks beaching themselves on a semi-regular basis, until some of them make it progressively a tiny bit further perhaps due to longer, sturdier fins and they could sorta waddle around the beach? And then freak mutations causing them to develop some sort of primitive air sacs for gaseous exchange.
.
It's simply nuts to imagine the sight: picture a static view of some beach fast forwarded across millenias, nothing but fishes beaching themselves until eventually they get limbs and lungs