I think the real issue with Cora is what he actually he brings to the table.
Cora's supposedly good with player motivation, which, in theory, creates hungrier yet looser players who will excel in the friendly environment created by Cora. In service of that environment, Cora takes a very predictable player-focused approach with scheduling, clear roles (insofar as they can be made clear), and deflection of player criticism in the media. Maybe he also has heart-to-hearts and bakes them cookies. (Seriously - I have no idea, but I'm willing for the sake of argument to credit that he's doing behind-the-scenes stuff.)
I have no doubt players like Cora and his approach, and I have no doubt he's probably an easy manager to play for, who can inspire some personal loyalty by having the players' backs. But does this result in any kind of net gain for the club?
I think there's very little evidence it does. In Cora's tenure, we've been just as likely (if not more likely) to see individual player performances plateau or trend down rather than trend up. (In fairness, I'm inclined to view the pitchers as more of a mixed bag (individual results wise) than hitting/fielding, with some real successes.)
When this lack of individual player improvement is combined with Cora's year-long philosophy and particular in-game choices, the result is very very meh. For example, if Cora's player-centric approach actually resulted in marked individual improvement (like the Rays) or cohesive synergistic teams (like the Rays), dropping a game or two because you're using a travel-day lineup is the price to pay for the gain. But where's the improvement? Where's the gain?
Just to be clear, I don't think Cora is a complete disaster. At the club-level, if he has a talent-heavy team (2018) he's good at long-term managing - the glitches and travel-day lineups don't hurt, as it really does average out. Plus he's shown he can manage competently in the post season.
However, if he has a more average-talent team, he's exposed in showing a remarkable lack of instinct for the moment - the ability to squeeze out a crucial win here or there. He's much more likely to maintain to his pre-arranged pattern of scheduled off-days. And, in keeping with that, not to pinch-hit or pinch run (although, this year he has changed in that regard, which is a good sign.) You can call it player-friendly, you can call it predictable, you can even call it a disciplined long-term strategy, but by nature that approach is simply not adaptive or opportunistic.
I'm sure Cora has protected individual players and motivated them. (In particular, I think of Duran - somebody like Valentine might have driven him out of baseball.) But despite that, Cora also keeps seeming to lead unmotivated and unfocused teams. For example, the 2019 team was, to use a word, coddled, with Cora constantly saying it was just a matter of time till they went on a hot streak. Again, it's that "will work out in the long run" view - until time runs out and it does not. (The times where he does get pressed, he tends to not show that kind of creative game management and rotation of players at the micro level - he'll go to his "chosen" guys overmuch. Barnes, Vazquez, etc.)
Now some outside factors (2018 to 19 hangover, 2022 strike, 2023 WBC) are not Cora's fault. However, I think that really goes to illustrate the fact that Cora simply does not have that fantasy motivational touch that people like to imagine he does. Or certainly not to the extent people believe it matters. Why? Other teams have faced the same issues and were ready for their seasons. Cora's teams. . .not so much.
The exceptions are 2018 and 2021. They are also the years without major off-season distractions. So, I'd concede that under ideal conditions, maybe he's an excellent motivator who can prep a club for the season. But that's really not saying much. If that's his big skill, why couldn't he leverage it to the club's advantage more than half the time? What about Cora's skill leaves it vulnerable to something like the 2022 shortened spring training when other teams, with lesser-communicators/motivators were not vulnerable?
(As a final PS, I'd note that sometimes the personal loyalty some fans have to Cora tends to invite absurd argumentation - such as the players being unfocused in spite of Cora's clearly superior abilities in that area. Meaning that because Cora must have a "+" motivational skill in play, it follows the players must be, collectively, an abnormally large group of "-" motivated individuals. Because if they weren't, they'd be playing better. What rotten luck for Alex.)