Margiknot
As far as I am aware they provide a different service with some take away style cross over. Pret mostly sell salads, wraps and hot drinks aimed specifically at the breakfast/ lunch/coffee crowd, to eat in or take away, whilst Greggs are a bakers that also make sandwiches, hot drinks and baked goods for take away breaks and lunches. Do Greggs in the north have seating to eat in perhaps ( our local ones do not). We have both in our local town and only Pret has seating. I occasionally buy bread/ rolls in tiny Greggs but would go to Pret to sit down with a warm drink on a chilly day.
A Greggs near me isn’t a bakery anymore, they used to do really good bread too
now it’s just takeaway type food which I never buy.