Hi!
ahigh makes a good point. You beat some hands he might play this way. Players can play quite differently in blind vs blind. He might have just a draw and a weak pair with 33 or a hand like AJ. He might be on a bluff with any 3X. He could even have J9, T9, Q9 or other worse value hands.
In general, folding the river with top pair is difficult to justify in a blind battle. We should very often show down top pair in blind battles, especially when we have a good kicker.
Getting 3-bet preflop and on the turn suggests to us that we're behind... but this suggestion only tells us that we should not raise again. It doesn't mean we should fold.
To decide whether we should fold we NEED to consider the pot size. At the river in this particular hand you'll be getting 11:1 to call. In other words, you only need to win 9% of the time to profit.
To recap, you may need to win more than 50% to make a bet or raise, but making this call is very different. There are quite a few bets in the pot already.
I would call here expecting to lose often but expecting to win often enough to earn a profit.