Some of the current issues were caused by Marchionne, Resta to Alfa for instance. And Marchionne is the one who removed James Allison and put Binotto as TD. By most assessments, Marchionne also wanted Binotto to rise to the top (SM's famous horizontal structure).
It's quite possible that the timing of Marchionne's death had more of an impact than his actual passing. When he died, there was no Plan B if Arrivabene left, other than to name Binotto as Team Principal. So, what happened is that when the showdown between Arrivabene and Binotto took place, it was either Arrivabene OR Binotto who was going to be left... i.e. a leader who had either commercial/political abilities OR a good relationship with the people who have technical knowledge, but not one could could combine both.
The management (Piero Ferrari and Camilleri) were left with a hard choice and and they made the wrong one IMHO, because Ferrari is still paying from Marchionne chasing Allison away (and the same for di Montezemolo pushing Aldo Costa out). They didn't want the same thing to happen with Binotto, but they've put him in a position that exceeds his leadership abilities, while not allowing him to use the techincal ones he has.
Right after Allison left Ferrari put out its best two cars in years... The main charge against Allison, allegedly (as we only know what one or another insider like Turrini leaks out) was that he was not extracting the potential of Ferrari's engineering depth & was only trusting his few chosen men. This situation probably preceded his terrible personal ordeal. Whether it is true or not, after he left you saw younger people like Sanchez (a Frenchman! something that Antonini conveniently forgets...) or outsiders like Resta & the GT's aero head (whose name I'm forgetting) assuming more responsabilities. Not to say that Jock Clear is English, or that the much maligned Rueda is a Spaniard, or that there's Germans, ex-Merc working on the PU department.
It's easy to forget now that when Alisson left, the UK press was rolling with laughter like there was no tomorrow because everyone, literally everyone expected Ferrari in 2017 to be utterly uncompetitive. And of course, everyone was claiming that Marchionne was just a typical Fiat-suit employing decision-making from the auto-industry into F1...
Marchion did only two mistakes, overall; shifting Resta to Alfa at a crucial stage of the '18 season; and firing Sassi, even if the jury is still out on that one: the Ferrari PU is right now at par with Mercedes'.
As for Arrivabene... Did he design the cars, did he actually have any technical knowledge at all? Because in current F1 even sporting directors like Horner clearly have a decent tech knowledge. Arrivabene, from what one hears both from Italian journos and English ones simply did not. Moreover, he had a very thorny relation with Marchionne, who hired him to essentially have a yes-man who would put a stop to all the leaks to the press. It was natural that after Marchion passed away he would try to get fully in charge of the team. What his indictment of the team personnel in the '18 Japan GP seems to have showed, IMO, is that the same bruising attitude he had to journalists was common to how he handled his own team personnel. He had to go, to put it simply. And his well known desire to bring someone from the outside, IMO, reminds me of Montezemolo's constant search for the magical foreign ace that at once would turn around the fortunes of the Scuderia (Costa out, marvelous Pat Fry in, ridiculous attempts to bring Newey in, etc, etc).
Anyway, with Resta back this whole drama on whether Binotto's shoulders were too heavily burdened is over. Binotto and Ferrari now simply need time & stability. It's ridiculous that every two or three years there are changes in top technical personnel when the tech direction of teams like RB or Merc has been the same, take one leave another, for around ten years...