There are certainly people on here who are using it to push an anti-car agenda. This is not the way to do that, because in most cases it's poorer people who live in Victorian small-house terrace estates without off-road parking, so such a move would be regressive. It should be done purely for the purpose of ensuring safe access for those in wheelchairs and with reasonable prams. (Noting that a 3-across megabuggy is not a "reasonable pram"[1] - I would use a standard 2-across one, which will be about the same as a large electric wheelchair, as the reference).
[1] Other designs exist if you have triplets.
With prams, it's not just the size....
Pavements are rarely flat or level, so trying to turn corners/negotiating obstacles/mounting kerbs on a slanty pavement with a double pram (or single pram with an older child in it) is quite physically hard work. Even worse for wheelchair users.