I think it is both, and then some.
I believe Josh made up in his mind starting midseason last year that he was no longer going to forcefeed Diggs all the time. I believe that is why we saw a drastic drop-off in Diggs' numbers. He was done with the diva mentality and everything else that came along with it. Now that Diggs is gone, Josh can just play free and toss the rock around to whomever without having to hear any crap about it on the sidelines between every series. Peace is something money can't buy, but the evidence of having it is undeniable.
I believe that Josh truly loves the game and has studied the game in prior years more than people want to give him credit for. I think he has always had an understanding of defenses since his breakout year in 2020. I do believe he's evolving and getting better, but I think he is truly getting better at playing free while still not being careless with the football.
The main thing here, something that I believe can't be overstated, is I think Josh really clicks with Brady. I think he clicks in the same sort of way with Brady as he did with Daboll. They get each other and Josh loves this offense.
Everyone on this team seems to be bought in and I believe Josh trusts them more than any other group he's had in the last 7 years. The maturation of JA17 is on full display. It doesn't mean he'll always be perfect, but the growth is on full display as a player and a leader.