Of course, the 18 is a perfect route for bendy-buses. How about a nice fleet of eCitaros?
This is why I think it was very short sighted to make the political decision of completely getting rid of articulated buses in London. They would be far more suited to routes such as the 18 than double-deckers - routes that are generally straight with a lot of short journeys.
Being on a busy double-decker in London is quite stressful, with everyone having to funnel through the corridor in order to reach the stairs, or to get from the stairs to the exit doors.
Many people don’t want to go upstairs because of mobility issues, carrying bags, or just the hassle of it. That is not an issue on a bendybus.
I know the topic was originally about buses on the 18 not stopping because of timing issues rather than capacity, but I’d also say timing issues would reduce with bendybuses. A concern is fare evasion, but TEC buses in southern Belgium make everyone board at the front, but then there are three doors to exit and no new passengers have to wait for people to get down stairs.