My take is just like we have allowance to introduce children to the concept of money, parents could use data allowance to introduce children to the concept of the internet.
The worst content out there is typically data-heavy, the best - not necessarily, as it can well be text in most cases.
Money is, depending on the country, slowly evolving from physical coins/notes to plastic cards to pretend plastic cards on smartphones, to the same but you need an app to manage the account, to let's stop pretending and just use an app in the first place.
The last one is difficult because you need a common standard, either someone becomes a monopoly (or two or three quasi-monopolies such as google/apple) or better still this is one of few cases where government regulation could do more good than harm.
I think China is already close to the last phase at least in cities, going down the government regulated route?
This is highly country dependent of course - in some places shops must accept coins by law, even if it's so unusual that you have to roll a critical success to get the right amount of change back.
I would like a world where we can give children physical pocket money rather than some abstraction, and they don't need a smartphone of their own to check their balance. But we'll probably have to fight for that at some point.
The worst content out there is typically data-heavy, the best - not necessarily, as it can well be text in most cases.