Modern bicycles (except new e-bikes with chain guards and internal hub gears) require degreasing and lubing every two weeks, These are not going to be very attractive to people who use other means of transport, because cars don't need this sort of frequent maintenance.
Yes and no. Modern 11/12 speed chains maybe, but my commuter (9-spd) gets lube every 4 months or so. Yes, I have to monitor the chain wear and change it every few years, but that’s not very complicated. It goes to the workshop less often than the car.
They’re more expensive, but you can find non-electric bikes with a belt drive and a gearbox or gear hub which are very low maintenance.
and there's plenty of companies making "city bikes" that don't require super-frequent mainenance and are designed for durability and ease of use. you can get a bike optimized for light weight, but you absolutely don't have to.
What's your basis for your claim of such frequent maintenance? Also, what do you mean by a modern bike?
But when I had a basic hybrid bike I similarly just cleaned it every few months at most when it got dirty from wet rides. Worked fine for years.