why do people think we need B&E to do more?
If you go back say 15 years you had HMQ supported by PP, Charles, Camilla, Andrew, Anne, and Ed & Sophie. 1 & 7 supporting.
William and Harry were both doing other stuff. They were asked to become full-time Royals as HMQ and PP were aging.
PP has retired, HMQ is 94,
Charles must be doing a chunk of HMQs work. So really you have Camilla - over 70, Anne - over 70, Andrew - no more, Ed & Sophie - working away, William & Kate, Harry - gone to become a filmmaker.
So at the moment you have HMQ / PC & 6 supporting. Give it another 15 years HMQ will be gone, PC, Camilla and Anne late 80s, Ed & Sophie, in their 70s. William & Kate. But their kids will still be quite young to be taking on the Royal roles.
Hence a gap for B & E to fill. Harry has left a big gap.