This isn’t all that difficult in my opinion. If you think Goff struggles with a bad team and thrives on a good team then great, what does that analysis get you? All that matters is what would a better QB do? If Holmes is drafting a QB to replace Goff then you should probably hope they are better and thrive even more on a good team. On a bad team you just hope they survive until the team is better.
Kansas City seems to have been confident that Mahomes was going to be better than Smith. The hope is you have evaluators that are right, and that they will make that upgrade when they see the opportunity.