I think the departures of Allegri from Juventus, Ferguson from United, and Wenger from Arsenal (and this season the departure of Ancelotti from Madrid) have shown other clubs that you can't just take a whole organisation - that's been behaving and playing and winning in an established way for years - and just put it on the shoulders of a guy who's been hired to carry on the exact same level of success and form another dynasty while also getting off to a flying start. All three of those teams (and Madrid this season) tied themselves in knots by going out and trying to land the guy who was going to maintain elite success without skipping a beat, even temporarily.
No Juve manager has made it to 60 games in charge since Allegri left the first time (in 2019), when they hired Sarri, then Pirlo, then Allegri again, and have continued hiring and firing an astonishing amount of managers for a club of their size. Sarri, Pirlo, Motta, Tudor, and now Spalletti have all been in the Juve dugout as permanent managers in the last seven years. Ferguson dumped the whole of United on Moyes' shoulders - big mistake. Arsenal dumped it all on Emery before giving the job to their Maresca equivalent in Arteta, another high-level manager who was largely untested when he was given the job. Madrid have re-hired Zidane and Ancelotti because they can't seem to get it right without them.
Maybe the best thing to do, long term, is to adopt the Barcelona model. Accept there will be a drop in standards, keep expectations relatively high, but don't pin it all on one guy to keep things going. After Pep it was Vilanova, after Enrique it was Valverde. Then after some faffing they landed on Xavi and now Flick. They're not the all-conquering, generational team they once were between 2009 and 2015, but they win titles on a regular basis, play good football, and - despite a gulf in financial power between them and Madrid - have been the strongest team domestically in Spain despite losing Messi and having basically no money to spend in comparison to Madrid. Maybe just having a glorified caretaker in for 2-3 years is the best way forward after someone like Pep.