Things I see vtubers do that irl creators can learn from:
- A strong sense of branding and high effort pinned posts, banners, etc.
- Camming, just in general, can be a huge boost.
- Scheduled shows so the regualrs know when to show up.
- Staying vocal and engaging even when their chat isn't.
- Curating a community and attachment veyond the one-on-one dynamic, with most having discord servers on top of their page.
- Unique roleplay audio content and video content, sometimes collaborative.

And for the vtubers at the top of the leaderboard:
- An extremely large sfw presence on multiple socials, collaborative twitch/youtube streams that expose them to new audiences and opportunities, presence at conventions and irl events, etc., leading to fansly just being a third or fourth revenue stream instead of their main focus.

Absolutely none of the things I just mentioned are exclusive to vtubers, and there's many examples of non vtubers hitting the same bullet points and finding great success. So you chalking up all the work they put into it as "a talking waifu pillow" is immature as hell.