I think the "rebuild" will be stifled by four things:
1. Mac Jones is high floor low ceiling... most successful rebuilds require an elite quarterback. If Jones had even Miami's skill position players then I'd feel better about it. Right now people are talking up Meyers as his #2. Ouch. Overall I actually like New England's skill players but collectively they're not good enough to elevate a quarterback to the next level.
2. Josh Allen is going ape sh*t on the division for the foreseeable future. Buffalo in general is MUCH better than New England right now.
3. The coaching staff has the potential to be a train wreck... specifically Patricia and Judge... and of those two Patricia since he seems to be Bill's main guy.
4. Underwhelming drafts.
Let me take your points one at a time
1. YOU have no idea what Mac Jones ceiling is. You sound like you don't believe what you see, but rather what you HEARD last April at the draft. Mac Jones had a GREAT year last season, not just a good one. He had close to 4000yds receiving as a rookie throwing to a very mediocre WR group and led them into the playoffs. He was the BEST of the 4 rookie QB's who were picked ahead of him. Now with a WR group that has added speed, size and more experience to that group (Thornton, when he returns, and Parker) The OL is STILL a work in progress, but if it gels as we hope, Mac CAN have a better year than last. You should put Mac in that "game manager" box (not that their's anything wrong with that)), anymore that you would have put Brady in that box back in 2000-2004.
2. Josh Allen IS the best QB in the division and the Bills LOOK like they have a better overall roster as well, I don't disagree. BUT Bill has been able to beat better rosters for the last 2 decades. That's the beauty of football. It's the one game where better TEAMS, beat better rosters.
3. The coaching staff has NOT been a train wreck. That is what you HEAR over and over again as the team goes thru the NORMAL ups and downs that occur when you make a significant shift in what you do on either offense or defense. And here's a clue. The defense is ALWAYS going to be ahead of the offense in camp. Patricia and Judge have over 20 years of coaching IN the NFL, they have PROVEN that they can coach over and over again. Patricia HAD ot master what offenses do in order to understand how to defend them. WHAT DON'T YOU GET ABOUT THAT. It might even be an advantage, understanding so well what moves defenses with take against certain formations, etc. I've said it over and over again. And despite the fact that both failed miserably as HC's, (BTW so did McDaniels), 99% of HC's eventually get fired, It doesn't mean they can't coach individuals and groups. Josh McDaniels got the play calling gig after just 2 years of coaching on the offensive side and 3 years coaching on the offensive side. Get over it.
4. Well this one is looking pretty good with FOUR players that seem like they will have a place in the regular rotation at their positions. (Strange, Thornton, JJones, and MJones. They also have a few darkhorses that may also stick like Roberts, Russey and Ray, right off the top of my head. Plus, Strong who looks he's going to go through the RB rookie year that so many have gone through. THAT's a rookie class that I'd take every year. But its about 3 years too early to really assess what this year's rookies will end up being. But even you would have to admit that "so far so good" would be a reasonable assessment to this rookie class.
5. One comment on where we are in the rebuilding process. The rebuild has one more year to go, because it will be NEXT year where we will be VERY active in the FA market that we will have the wherewith-all between FA and another draft, that we will be able to fill in all the holes we find this season. So in 2023 the Pats will have a good QB with 2 years experience under his belt and more talent than he's had so far.
Remember for some teams looking at the complete rebuild like we are going through would be happy going from 5 wins to 7. In our rebuild we had to "endure" 2 teams that won 7 games and then 10. Christ back in the day Bills and Jets fans would be THRILLED with a 7 win season. Spoiled Pats fans look at these 2 season as abject failures. Go figure