Yes, I knew a few of the authors from my time in grad school. Certainly much closer to mimicking the enamel structure but not a commercial therapy yet.

I don't know too much about the bacteria stuff. Regarding enamel, the native structure is very intricate and contributes to the properties. Most of the acellular chemical reminalization just deposits disorganized minerals on the teeth. It might be improved vs. doing nothing (I'm not sure but I do use fluoride reminalization from the dentist) but its not regenerating your enamel. Imagine just slapping some concrete or mortar all over a slowly decaying intricate brick wall vs. rebuilding the brick structure; you may mitigate complete collapse but you didn't fix the decaying brick wall.

Self driving cars have had many incremental improvements. I think fusion power is actually making progress, not clear about solid state batteries. Seems more companies closing than making solid progress.

I did my PhD in an adjacent area and its not clear any of these come anywhere close to regenerating your enamel.

I thought the insect breathing work at the synchrotron was cool https://www.science.org/doi/10.1126/science.1078008