He is going to need to be able to win games with his arm at times. If he's only a QB who can throw it when the run game is there, then they made a mistake and will need to reload the position.
So for right now McVay has to dial up passes for him and force him to learn or fail. I mean if you think you can run the ball into a stacked front every play and sustain drives I have some beachfront property in the midwest to sell you. Miami basically said "we don't think you can beat us Jared." And if you can't beat a cover 0 as a QB then teams will single up outside, bring the house every play, and stuff both the run and the QB regardless of the call.
The only thing in this league that keeps a defense from playing downhill and attacking the LOS is the passing game. It's a delicate balance and one McVay is very good at, IMO. Problem is sometimes players fail and/or don't execute and sometimes opposing DCs put up good gameplans that can slow you.