It’s not difficult if you’re on newer versions of iOS and Android. It’s easy to customise notifications or turn them off altogether. If you’re less techy, then it’s more difficult.
The problem is the apps assuming they can send you tons of notifications by default. Plus some apps keep adding new notifications types and assume that people are interested in them (for example shopping apps starting to suggest random products or Instagram advertising the creator’s broadcast channels).
It’s good we’re highlighting the mental burden of constant notifications as some people are not aware of it.