Both Apple & Google has implemented so called 'well-being' features which show much we use each app, in the case of Android10 it's even possible shut off few apps for a defined period. The thing is, businesses generally refrain from 'teaching etiquette' to their customers especially if it involves changing decade old habits.
>Is the interest level among their customers that low?
But there seems to be a need gap for smartphone detox, hence dumb phones like 'Light Phone 2' was able to meet its campaign goals at indiegogo - https://www.indiegogo.com/projects/light-phone-2#/.
I personally have notifications disabled on almost all of the apps, if not tightly configured and even those notifications I receive gets sunk into a smartwatch stuck to my desk.