People will give the Browns all sorts of grief if Wentz becomes an all pro but the grief will be misplaced.I think you're letting the Browns off too easy. I suspect people in NFL circles were pretty sure the Rams wanted Goff by the time the Browns dealt the pick, so the trade was fundamentally a bet against Wentz -- if he becomes a league-average QB by his second or third year, his value will swamp the value of the picks the Browns got in return, unless they fall ass-backwards into the next JJ Watt or something.
People talk about the Rams fleecing Washington in the RG3 trade, but the Rams are still waiting for their first playoff appearance since that trade, because their QB situation is a train wreck. We'd be looking back at that trade as a disaster for the Rams if RG3's career had played out to even the 30th percentile of the range of expectations at the time he was drafted.
Results-oriented evaluation of these trades is fundamentally wrong. It is the equivalent in poker of saying that somebody was dumb for folding against a massive bet when drawing to an inside straight because they would have gotten their miracle card and won the hand. Or looking at a roulette ball that landed on black and saying somebody was wrong not to bet all their savings on black.
Decisions need to be evaluated based on the information you had at the time the decision was made. If somebody wants to argue that Wentz was such a great prospect based on the available tape and other information that the Browns should have turned down the Eagles offer, that's a fair argument. But what Wentz did later should be irrelevant.