What would have happened if the 49ers selected Mac Jones or Justin Fields at #3 in 2021?

OK I appreciate there have been a lot of Lance threads here today but I'm going in a slightly different direction...

What if the 49ers had traded all those picks to take a different QB? How might things have worked out for the 49ers and for the QBs concerned...?

Mac Jones - I think the immediate narrative would have been far more negative after the pick was made, than it was when they took Lance. Everyone would have said you didn't need to trade up to #3 to take Jones and you're just getting a guy with similar ceiling to Jimmy G. But I think over time this would have been good for the 49ers and good for Mac. He would have done the things that Brock Purdy did but better, he's a more polished and accurate passer. I think he would have worked well in the Shanahan system and he wouldn't have had to deal with Matt Patricia as his OC in year 2. Probably at this point both parties are pretty happy with how things are working out even if the suspicion remains that the 49ers overpaid in the draft.

Justin Fields - I think he delivers what Shanahan was hoping to get from Lance ie a top tier rushing QB who brings a new dimension to the 49ers offense and makes them far less predictable than they have been. He needs to grow as a passer but I think Shanahan would scheme players open for him and with Deebo, Aiyuk, Kittle he would have achieved more as a passer so far than he did in Chicago where he was playing behind a terrible O-line and without much receiving talent until now they have DJ Moore. I think Fields would be ahead of where he is now in Chicago and the 49ers could be a really dangerous team. Possibly Fields is on a Hurts type trajectory if he lands in San Francisco.