Lamar has things to work on yes. But a lot of folks think he's a bad passer because he doesn't pass for a lot of yards. Passing yards is a stat mostly based on volume and shouldn't be the qualifier to whether someone's good or not. I believe four of the Top 5 leaders in passing yards in 2019 all missed the playoffs. If you're passing a whole lot that usually means your team is down and your offense is unbalanced
The Ravens offense is a run-first scheme. In that case (really all cases) efficiency is better than volume. How good are you in the opportunities you have to pass? Lamar is really good in the intermediate and downfield passing game
The problem I see with the Ravens offense is that they don't have anything in the short passing game. When the running game is stopped you can't just go for shots down the field, simply moving the chains is fine enough. Lamar has to work on the dink and dunk game, which is ironically the part a lot of people think he's good at because he doesn't pass for a lot of yards