How does blocking gambling, crypto, and adult content help their bottom line? Seems to me like these would be a lucrative source of income if they allowed them on the store.
The risk to the average user is that an app they want is removed from the App Store and only available via sideloaidng.
Adult and Gambling have different compliance requirements with banks and payment processors, some outright don't allow dealing with these types of content/marketplaces (have a look at Stripe's T&C as an example). Apple and Google would rather not get into these markets than dealing with the legal complexities, this is the reason they are blocked. If they were doing it for the good of the users they would have just blocked them for underage users.
> Apple and Google would rather not get into these markets than dealing with the legal complexities, this is the reason they are blocked
I find this claim pretty suspect. What are you basing this on? I'm sure the extra income would be vastly more than the cost of dealing with legal complexities.
The risk to the average user is that an app they want is removed from the App Store and only available via sideloaidng.