Magni seemingly was never satisfied with his experience. From Day 1 he wasnt happy about his model, his creativity being scratched, and had random outbursts of anger risking brand droppage like his giant Overwatch rant. According to Lando he left because he (and according to him Vesper) that he was insulted for some reason to the point of going to therapy for his issues with company. To me personally, he didnt look at what holo is on the creativity side where there are so many rules and regulations you have to follow, which makes him kinda seem to step on a rake himself. He seems to be still close to all the talents still tho.
Vesper was being increasingly more upset at the rules and perms to the point where he lost all the love of not only holo but streaming in general, on top of his general anxieties and shakiness on the do and donts of company rules and in general collabs where he admits he panics a bit. I wasnt too surprised if he even went to JP to see if he can handle doing anything without his meds and it seemed like he failed the test to him. He was convinced to come stream back as Randon after Lando convinced him to keep on streaming. Recently I think I seen someone say he mentioned that he now thinks of his time at his past job in high regard and was proud he did it.
That reminded me, yesterday at night I was going through youtube vids, and I stumbled upon this clip of Kiara and Shiori (from their off-collab handcam stream they had with the Ouija Board back in july of this year), and seeing Kiara's reaction to the long forgotten, probably biggest fumble of Hololive-EN history, easily, in Omega Alpha, but with what you said Asphalt.
It reminded me that, wasn't Magni and Vesper, since that was back when Holostars-EN debuted, and I believe if both had huge gripes with the rules back in the day, wasn't that also with the whole unicorn shit of fans and simps that didn't want to see Kronii together with Vesper? Basically, when Omega Alpha was a thing, and this was all news to me, apparently the entire management of EN was awful, perms blocked up the ass, lack of freedom to do a lot of shit, and I could imagine a link to what could be the sense of being "trapped" in rules and japanese work bureaucracy could have been around the brief time, the person behind Omega Alpha was in "control" of EN, as what they intended for it to be was in a role similar to A-chan was for JP.
This isn't certain, but a lot of comments, and clips at the time, pointed out and showed a collective sense of disgust, anger and pent up frustration that once Omega Alpha (both as an entity, the person behind it and as a project was dropped entirely) seemed like all of EN (and I believe this was post Magni and Vesper's "termination" graduation) felt like a huge breath of fresh air, which could allude as to why the rules were so uptight and much stricter during that period around 2021-2022.
Again, this is just a huge headcanon of mine, apologies for the long wall of text.