like many things it's a bit more complex - a better OL in and of itself doesnt solve cover 0 because the very nature of cover 0 means that someone's coming free unblocked (unless someone manages to block 2 defenders at once) - that being said it becomes far easier for a QB to read and react vs cover 0 when they trust the OL and their ability to make the right calls and reads in protection so that only 1 defender comes free and that they come free from the expected spot - that's partly why Lamar was so good in 2019 because we'd put him in an empty backfield and spread the defence so that it becomes less crowded in the tackle box and easier to read the blitzers and then he trusted the OL to pick up everyone and leave just 1 unblocked defender blitzing off the edge to him
now lamar has to do better actually reading and dealing with those blitzers coming free - in 2019 he was able to deal with them in all sorts of ways but in 2021 he struggled to read the field - what's more is because a lot of it in 2021 was happening on 3rd down, lamar was reticent to throw underneath to the hot read because they'd be short of the sticks - 2 easy ways to get lamar more confident in taking those hot reads is to put guys in the slot in those blitz situations who you trust to make a guy miss in space or break a tackle and get upfield or it means getting chemistry with bateman (or someone else) on the outside who you know inherently has a 1v1 matchup and you throw the backshoulder on a vertical route to him - you can also run a vertical route (preferably a seam or a post) out of the slot where they have a natural 2-way go and you've got middle-field open because both safeties are either blitzing or in man coverage
that's where the play designing comes in and that's where general coaching comes in and that's where chemistry and communication are super important also - lamar and his receivers when they see those pressure looks have to understand when to adjust their route vs the blitz - communicating which guys blitzing trigger those hot calls and adjustments
ill put it this way - lamar looked a bit flummoxed in the dolphins game (and the few others before his injury) - a better OL massively reduces the level of difficulty for him but he still has to be better - and obviously a better plan than simply running quick slants for 6 yards on 3rd and 10 from the coordinators - and we need to put receivers in good positions to make those plays
ultimately as with everything, execution is more important than scheme and design albeit those are still important
