Here's what Coco actually did:
1. She supercharged the idea of full gen contributions to content, which existed but had been rarer before Asacoco Live. Like, first gen barely existed as a group, second gen only really gained their group identity later, third gen had some shared content but mostly in smaller slices, most people didn't know Miko and Sora were the same company... but everyone knew fourth gen as a unit thanks to the skit component of Asacoco Live, and that carried forward to future gens and HoloEn.
2. Deliberately or not she normalized superchat culture on YT vtuber streams. I'm willing to bet most indies would earn half the donations in the universe where Coco never existed, because superchats were stillborn as a feature and one of the primary selling points of Twitch was the donation culture vs YT. That's still the case for non-vtuber YT streamers.
3. She kept the English-speaking audience that had started to grow for Hololive since the Azur Lane collab and the early 2020 memes warm and interested until Myth arrived.
4. She hosted one of the only completely regular collabs across all gens and branches. The combination of Asacoco Live news segment and Meme Review collab content enabled cross-exposure and sharing of audience between talents on a scale never seen before in the company, and combined with the rest of this list helped enable the Hololive subcount explosion in 2020 and 2021 as far more of the audience was willing to cross-sub.
5. She blew up the (now dying) Hololive Reddit into a place that got on /r/all daily, and did so at a time when half the western world was online and looking for content.
6. Accidental, but she got Hololive out of China, which wouldn't have worked out the same if she was not single handedly more accomplished than the entire HoloCN brand, because of all the previous points.
I don't give her credit for EN either, that's more meme than fact, but I'll give her credit for expanding collab attitudes, increasing general exposure and cross-company exposure greatly, and superchat culture. It also seemed evident to me that after she left upper management did some house cleaning, though not substantiated by anything, just schizo reading between the lines.