It's actually much less safe in most places. The speed differential between bikes and pedestrians is too high, and drivers can't see cyclists as easily when making turns or pulling into/out of driveways.
Writing as a cyclist who rides in the street, and used to ride on the sidewalk occasionally.
As a casual and unfit cyclist who doesn't break 10mph i think there should just be a "you can ride on the footpath if you're going at less than running speed" rule.
Fine, but people that bike as a principal mode of transport are not going to stay under 10 mph.
Can't really agree. You need to have your head on a swivel when cycling in any event, and since walking in the US is as unpopular as cycling for commuting, sidewalks in my suburban area are generally empty as far as the eye can see. But even in the case of a bicycle vs. pedestrian accident, both parties will generally survive. Car vs. cyclist, I lose.
It's not about you seeing the car, but the car seeing you. Consider, for example, cars turning right across a crosswalk while a cyclist continues straight through the intersection on the crosswalk. The driver's visual scan will catch pedestrians but not you, since you are nowhere near the intersection at the time they look but in front of them by the time they start accelerating. If you were in the street, you would appear in the right side mirror.