Why should gambling be the exception? One could argue other app-based vices are just as bad, if not worse.

Crippling debt from unwise impulsive gambling by a teenager is probably worse than whatever occurs from a teenager scrolling Twitter all day.

The latter may not be great, but eating potato chips all day also probably isn't, and I don't think the government should outlaw minors eating potato chips. Plus it's variable: some get positive, educational, pro-social, productive outcomes from social media and some don't. Gambling is always bad in the limit.

A simple rule could probably be that if a website can make you lose over $200 of real money, it should probably require age verification. I don't see why other things should.