Sidewalk ownership and maintenance should be a local government (usually city) responsibility. Homeowners should not need to contribute to any sidewalk maintenance costs, nor should they be held liable their falling into disrepair (unless the adjacent property owner was responsible for such damages). However, homeowners or business owners adjacent to the section of sidewalk in disrepair should take it upon themselves to call the responsible agency to report the condition of the sidewalk. (Anyone who notices that any public property is in disrepair should, as a responsible citizen, take it upon themselves to call it in.)
Perhaps to make the maintenance of sidewalks easier, they should be built into prefabricated standard-sized slab sections which are 2 meters long and 150 centimeter wide. (This should be the standard width for residential sidewalks.) All sidewalks should be built with strong, crack-resistant, and durable materials including rebar or possibly using other materials or techniques. They should be built in such a way that ensures their extreme durability.
Sidewalks constructed in this manner could easily be removed by either a group of workers using manual cranes or a crane mounted on a truck parked on the street along side the segment of sidewalk needing repair. The sidewalk’s subsurface could then be releveled by having workers cut any offending roots, fill in soil, etc. Furthermore, access to underground utility lines or other infrastructures could be more easily obtained with this system of sidewalk construction. When the workers are finished, they simply replace the same segment of sidewalk. If the slab is in need of replacement, they could just replace it with another slab, since they would all be of standard dimensions. Though normally utility lines run underneath the street surface, it is often frustrating to have the street cut up and patched (and living with the street scars for many years) to fix something below. But of course there may be many other obstacles near and under sidewalks like individual home utility feeds, tree roots, beautiful parking strip landscaping (including trees), etc., that would be practical inhibitions. But maybe with better long-term planning (placing sidewalks immediately adjacent to the curbs of streets), such a reality could occur.