Yes, super-recent developments may obviate hills, but 40 years of city design have already happened. The Netherlands case was easy mode, and they leaned into it while extending their cities. That's not useful for almost any other country.
Also e-bikes are expensive and heavy, of course, so they're a good gentrification measure, if you're into that sort of thing, but they aren't for everyone.
And cheaper and less heavy than a space shuttle. But neither will seem that relevant when it comes to parking and securing your electric bike when you live 5 floors up.
Lack of parking can be a barrier to adoption with any type of bike. Nobody wants to lug any bike up stairs.
But it's a solvable problem. Newer apartment buildings in London must provide secure cycle parking for residents and visitors.
For older buildings that lack such provisions, London councils often provide secure (covered, lockable) on-street cycle storage facilities. 1 or 2 car parking spaces can be converted into parking for many bikes! [1]
Also e-bikes are expensive and heavy, of course, so they're a good gentrification measure, if you're into that sort of thing, but they aren't for everyone.