I don't think anything he found could come close to bankrupting any of the companies... but I agree he should be receiving a more significant award, even if the companies don't have a bug bounty program yet.

Most of them are early stage, most of them just can't trust a random email,Some of them want to save money for facebook ADs. That's how startups work these days.

Are they better for corporations and larger companies?

larger companies like Oracle,Adobe hardly give a damn. Sometime they say "Thanks" that's it