Articulated buses have their place.
In Scotland, they are used extensively on a number of services that cross river estuaries on high level bridges (eg Forth Bridge, Tay Bridge, etc.), because in high winds, all high sided vehicles are banned from these bridges. So articulated buses are a good substitute for double deckers in this context.
They also have a place on services where conflicting passenger movements on and off the vehicle are infrequent.
Some European cities use articulated vehicles both because their road layout is more "spacious" and also because the ticketing system is simpler. Neither applies to London.
How would you fancy travelling around in a car designed in the late 1940s, the early prototypes of which first took to the roads FIFTY THREE YEARS ago?
NO?
Then why hark on about Routemasters for? A good sturdy vehicle for the 1950s and 1960s - YES. For the 21st Century - NO, NO, NO
Remember that the only warm part of a Routemaster is in the lower saloon close to the driver. Do not forget the high boarding step and the steep stairs to the upper deck. Disabled-friendly - you must be joking. And then there is the engine, just one of which adds more to global warming than half a dozen modern buses.
Routemasters have their place - it is called a museum.