Biodegradability would be great, except one thing, tires are exposed to the environment and elements constantly, youd be having to replace tires much much much more frequently.
Recently saw an article[1] talking about potential tires similar to what was used on the moon rovers, which is a woven steel, this could be a great solution, exceeeeppppt so many roads are a disaster between lack of maintenance and debris, that youd likely have to deal with busted tires more often. The upside though is that the worst that happens is you get a hole that causes uneven ride and eventually a bigger hole. No need for air in the tire as its just a woven steel anyway.
1: https://www.newsweek.com/scientists-look-space-rovers-limit-...