I personally think it could be a great alternative to cars and bikes for those who need to take a whole family somewhere or a decent amount of stuff.
Only modifications I would make would be ride-by-wire and an extra set of pedals (so you can have two people pedalling without the annoyance of normal tandem bikes having to pedal at the same rate), and a more powerful motor (only 250W is legal in France, where this was designed, whereas 500W is legal here in Canada)
This has already taken off, just not with people: https://www.google.com/search?q=lastenrad+paketzustellung&tbm=isch
https://cargo.mubea-umobility.com/
And yes, they are a bit of an issue, but way less than ordinary delivery vehicles parking on bike lanes and sidewalks.