It’s a bit chicken and egg. Getting those first sats into users hands without having them jump too many fiat hoops is the issue. Cashapp probably does this best so far.
The next big jump may well be a gaming or streaming platform.
If people get their first sats from a view/play to earn scheme (e.g. watch this ad and we give you 100 sats) that might be enough to get the snowball rolling.