@SleepingStandingUp bit of a drip feed that, that you don't just have twins but also a 4 year old on o2 - in which case your buggy is medical equipment/aid!
My point was, if everyone who CAN, reduces the size of the gear they use, there's more space for those who cannot. I haven't once said buggy pushers shouldn't be on buses, and in my initial response I pointed out, some of those buggies are actually 'medical equipment' ie, wheelchairs 'in disguise' -but some folk would prefer to pick an argument I never raised!
If bus companies demand that you fold a pushchair and cannot bring unsuitable equipment on the bus (just as you cannot bring bicycles or large mobility scooters on the bus), then manufacturers will be forced, by the demand from parents, to make better designed, easier to fold one handed, equipment.
Currently the situation seems to be that buggies are VAST, parents are in competition with each other to have the latest hugest, 'safest', bestest buggy that is designed to fit in the back of a big car NOT on public transport, and the very last thought anyone has when buying it is 'can I fold this down one handed at the bus stop to get on the bus'.
If I have to buy multiple pieces of expensive equipment to get ME around, for the entirety of my life and fit in with the various places I go and transports I use, why don't others do the same?