It all started in February 2012, with Malév ceasing operations and Ryanair announcing they would open a base here in a few weeks. Terminal 1, used by low cost carriers, was already near its full capacity without Ryanair, while Terminal 2 became almost empty, so the airport decided to close Terminal 1 and move all operations to Terminal 2.
Terminal 2, however, was not planned to be used by LCCs (though it was, temporarily, in 2004 and 2005, until Terminal 1 reopened after a renovation.) Budget airlines obviously didn't want to pay more than they did at T1, they didn't even want to leave the good low cost terminal, but getting the same services as legacies for less money wasn't an option either. If I remember correctly, Ryanair originally used stands near the terminal without using the jetbridges, while the other low cost carriers still used T1. I believe this may still be the best option, maybe there just aren't enough stands at the terminal for all airlines or the airport still asked too much for it.
The next step was closing a taxiway and using outer stands with passengers walking to the aircraft. This was used by Ryanair and easyJet on their Schengen routes. However, this was quite a pain in the summer heat or in rain, partly beacuse, I think, boarding was usually started way too early. Then they moved the boarding gates from inside the terminal to tents without aircon/heating, toilets or anything, but at least you wouldn't get soaked. Up until this time, I believe, all non-Schengen low cost flights used buses on boarding.
This spring, the tents were replaced by these 'terminals' (they were build both on the Schengen and non-Schengen part), which are just a bit better than the former. I actually thought they at least had some air conditioning.
They opened around a month ago, but not all easy/Wizz/Ryan flights use them. Wizz still uses buses on several of its Schengen flights (not sure about non-Schengen apart from LTN
), and I flew Ryanair to Stansted about a week ago and we were bussed to the aircraft.
I haven't tried them yet, but I think I will next week. Lack of aircon worries me a bit, but still not sure it's worse than standing in a bus for 30 mins. I really miss T1.