A slight exaggeration, no? Whilst it's uncommon to find a pub that doesn't do food, I can think of several not far from me. (just outside Brighton).
And "a pub that does food" is still quite far from being a restaurant. Some only do food on Sundays, some have limited menus run by guest kitchens and some get the food cooked by a nearby takeaway with whom they partner.
It starts with Sunday lunches, and slips into weeknights.
It starts with order at the bar, and slips into little “reserved for diners” signs on most of the tables.
It starts with the barman working the sandwich toaster and slides into teenagers in white blouses and knee length black skirts with name tags saying “trainee” asking you to wait to be seated as you enter.
Pubs used to be adult domains where people went to drink and chat in the evenings. Now pubs put playgrounds and bouncy castles in the car park to bring in families to dine.
Of course there might be some classic true pubs left? Perhaps someone should make an app ... arrrgh!
When I visit London, it's not difficult to find a pub with no children and no food.
Things have changed, but you are exaggerating it.
And drama!!