Yeah I've watched a few Browns games this year and I was thinking about what a fan you were. I think he kind of sucks. Certainly wouldn't take him over Dak.
He's definitely struggling at the moment but a lot of that is attributed to having to play behind one of the worst OLs in football. What the Browns have essentially done is place the engine of a 1979 Ford Pinto (the OL) into the body of a 2018 Aston Martin (the skill position players).
Using your Dak comment as an example. Even Dak struggled and was inconsistent when he didn't have the proper pieces around him. Most people on this very board said Dak sucked in 2017 and parts of 2018.
From what I've noticed it seems that over half the time Mayfield takes a snap on passing downs, he ends up running for his life in under 2 seconds because his OL has already allowed a pass rusher through. But there are also too many times where the OL actually holds up well but Mayfield still scrambles outside the pocket.....possibly because he's so used to having to run for his life that he's doing it out of muscle memory. Historically he hasn't been one of those QBs that makes one quick read then breaks the pocket. Last year and dating back to his college days at Oklahoma he hung in the pocket well, even against elite SEC defenses. So I think this is just a this year problem that will be sorted out down the line once John Dorsey can rebuild that train wreck of an OL.
The Browns OL isn't going to get better this year so Mayfield and Kitchens need to be better. That means adjusting the playbook and scrapping most of those long developing plays. They tried that a little last night but unfortunately for them the Rams are perfectly equipped to defend hot routes and other quick passes. They (the Rams) have one of the better defensive minds in the game at DC, an all time great DT, and a couple of good veteran CBs who are talented and savvy enough to take away hot routes and make QBs hold the ball a little longer.