What are your favorite examples of founder-led marketing?

By founder-led marketing, I'm referring to scenarios where the founder/CEO "is" the marketing.

Some successful examples I've seen are:

2)Richard Branson and Virgin, although he did this before the era of social media.

3)Justin Kan and Fractal

I'm working on an app and am trying to understand what I can do on YouTube and TikTok to market my startup.

Thank you!