lol why do you check turn?

I don't know exactly, I think I didn't have a plan to the hand while I was playing

I just didn't know much about what was his donkbetting range, but people normally donkbet draws
I was kinda worried about getting check/raised on the turn and have to fold a good hand knowing that he could(?) be bluffing with random cards, or a big diamond since he was kinda maniac
so I decided to pot control, plus, don't think he would call a flop raise, turn and river bets with toppair

my first thought was to bet fold river, but then I realize that he probably wouldn't check the river with the flush and miss value vs my tpnk/overpair or whatever people pot control with, and it's a good spot to turn your hand into a bluff on the river, since I don't have many flushs in my range after checking behind the turn, but I could be valuebetting better than his T8o
didn't know he was smart enough at the time to think about all that shit, so I'm not sure if I missplayed the hand or what

good players if they go for a x-r turn, they do the same on the river

but good players like that are rare