I think the tricky part of that strategy is you're not guaranteed to replace any of those players with someone just as good (nevermind better). You CAN improve on someone like Godchaux, but you already know what you have in him (and overall, it's good for his role). You CAN get a more well rounded edge defender than Jennings, but he's going to cost more and again there's no guarantee the next guy you bring in will even match him.
The more guys you replace, the more chaotic the rebuild becomes. So they brought back guys that played well and were bought in, to keep some stability on the side of the ball that actually did its job last year. In the meantime, of players who played at least 20% of the snaps on offense or defense last year, they've moved on from
Mac Jones
Ezekiel Elliot
Devante Parker
Trent Brown
Ty Montgomery
Connor McDermott
Mike Gesicki
Myles Bryant
Lawrence Guy
Jalen Mills
JC Jackson
Mack WIlson
And while they haven't yet, it would not surprise me if these four players aren't here after camp (or don't play 20% again this year):
JuJu
Antonio Mafi
Cole Strange
Shaun Wade
That's still a pretty large chunk of snaps that are being turned over, as well as the entire offensive coaching staff. And I would expect there will be more change in 2025. I'm not sure how much change people actually want in one single offseason before they feel like it's enough.