Surely the ability to recycle/repurpose an old tyre matters more than the flats, so I'm not sure how this helps. Also, I see the biggest concern as degradation

Surely the ability to recycle/repurpose an old tyre matters more than the flats, so I'm not sure how this helps. Also, I see the biggest concern as degradation of tyres contributing to rubber-dust pollution: "according to the UK government, and they are the second largest source of microplastic pollutant in oceans after single-use plastic" Seems like it would be better to find an eco-friendly alternative to tyre rubber instead. If this design allows that (e.g. by allowing tyre materials that aren't as stretchy as an inflatable would need to be) I'm all for it, but that's a more complicated definition of "good for environment", dependant on other tech being developed.