There are lots of reasons to think the Patriots will make a big jump in talent in 2025-26 based on where they will draft (four in the top 80 selections as of this writing), the mountain of cash they have to spend ($139M according to Spotrac), and a full year of experience by the new GM, front office, and coaching staff.
In an odd sort of way, the Miami game was useful to sear into the collective brain of the organization just how important it is to address the offensive line. Right now, they should be looking to replace the OL coach. Every year for 20+ years, Dante Scarnecchia delivered an improving OL that knew how to approach pre-snap errors. Some of those lines were stone walls, others were patchwork groups due to injuries. Scarnecchia never lowered his standards. Just pay the best OL Coach in the business and add three new players.
Let's say David Andrews, Mike Onwenu and Cole Strange come back next season. They have the two rookies from this year coming back. That leaves them with the need for two or three players who are upgrades - a rookie center and two tackles would be necessary, preferably a veteran LT and first or second round rookie. If they do that, the offense improves.
On defense, add a top-flight edge rusher and see what Bentley can do. From a talent perspective, there's plenty of defensive talent. Getting Peppers back this week to work with Dugger in the defensive backfield will improve things.
If they address the OL and add an edge rusher that commands attention, they'll spend a bunch of money but still have picks and money left to strengthen other areas - WR, RB, DB. Let's say two of four new guys in the trenches are rookies and they spend $30 million combined on two veterans. They'll still have lots of cash to pay a veteran receiver. I hate the diva WR who sucks all the oxygen out of the room, but maybe they have to do that this year.
Staffwise, I'd keep Mayo and his coordinators. Continuity is important right now and there's no reason Mayo won't get better. The weakest link on the coaching staff is the OL Coach who is not effective.