Perhaps because you don't have a disability or a stroller with a young child so that you can comfortably and effortlessly avoid them...
But sure, as a plumber to come to your house on his bike. See how that goes.
The footpaths have been rougly the same around where i live for 4/500 years.
Before cars your 400 year old road was mixed use, and your plumber certainly didn't turn up in a box van. When cars turned up, everything got pushed onto the sidewalk to make way for cars. It wasn't so long ago, there is no shortage of film of how cities used to be before cars.
https://i.imgur.com/8piPcuf.jpg
These schemes provide value to the user because they can be wilfully discarded anywhere.