That isn't true. Pedestrians put more pressure on the ground than cars do. Google it if you don't believe me.
The reason sidewalks last so long is they're made of cement rather than asphalt. If you made roads out of cement they would last just as long if not longer.
And the reason they make sidewalls out of cement is they have to. If they made then out of asphalt they would decay very quickly.
Have you ever seen an asphalt bike lane age? It never gets potholes. The top layer just expands and contracts or is invaded with tree roots. Over time the elements wear out the tar and the gravel loosens.
Compare that to a road where the truck literally forms grooves into the asphalt. It ripples like the viscous material it is in those conditions under multiple tons of weight. An intersection by me looks like its plaid with the grooves from perpendicular trucking traffic. And cement roads do last a long time but they aren't indestructible. I live on one. Trucks damage them and crack them up over time and the city has to fill in potholes. The more construction going on the more damage. Any big apartment build just destroys the concrete apron and sidewalk on the lot with the equipment because its that heavy. Orders of magnitude heavier than any human on a bike can be.
The reason sidewalks last so long is they're made of cement rather than asphalt. If you made roads out of cement they would last just as long if not longer.
And the reason they make sidewalls out of cement is they have to. If they made then out of asphalt they would decay very quickly.