Now if you're actually talking pure entertainment, as in simple "man these streams are just really good" type stuff. This is fundamentally not going to change when people leave Hololive. Part of the appeal of v-tubing, at least for me, is that you get to see a certain amount of people's personalities, and Hololive in particular understands that and tries to let the girls shine where they can. There should never have been some unrealistic expectation for them to be someone different, unless they were working for a shitty corporation....
...which brings in the ex-Nijis. I'll be blunt. All of the ex-Niji talents who cared about their content in the company still care about content. Mint cares about concerts and idol stuff. She has done more of that in the past year than she did in her time at Niji. Her normal streams have, if anything, improved. She can use game mods, shit on bad games, talk about the horrific romance novels she goons to without fear of getting suspended for brand risk, and screech about how much she hates Haley Joel Osment's tiny face without fear of repercussion.
Matara still is the same person, making the same content (mostly on twitch though

). She has also purged her fanbase of Nijisisters and can interact with guys like Bricky about Warhammer and Halo lore to her heart's content. She can go to conventions and mingle with people to her heart's content. And yes, she can occasionally post pictures on twitter of her IRL dress, and then blab about IRL dresses for 5 hours on stream without getting hammered by her boss for it. The rest of her content has not particularly changed.
Michi, when I've had the time to watch her, has seemed much the same. Weird sheltered Indo version of Shiori, same as always.
Dokibird got to arrange a bunch of mega-collabs and tournaments featuring both independent and corporate v-tubers. She is trying to become a brand ambassador for Marvel rivals to hide the fact that she is cripplingly addicted to it. She is coming out of her shell slightly and improving her life at home. Her overall balance of content is more FPS focused but the streams themselves have not changed.
So why are you expecting streams where, despite the fact that you have known these women for years, they're suddenly entirely different people who are also better at content creation? Dooby's streams are the same as Ame's because she IS Ame. She gets a way bigger cut of her income, she gets to use her home 3D in all of her streams for weird fun shit like driving a little car around or working out on monkey bars, and she gets to have her brother on stream screeching about Fortnite without having him sign an NDA or asking her manager first, that's what she gained by leaving. The goal here IS for them to stay the same, because now they're making more money, are happier, and can play games like Deus Ex without 10 years of permissions autism. They can use minecraft performance packages that aren't terrible. They can collab with friends outside the company on demand. They own their own IPs and models. These are not small benefits.