Nah, he could have pardoned them before he left office but as usual doesn't give a flying fuck about anyone except himself. These idiots don't realize they were simply tools used and then discarded.
However, I could foresee a scenario where another candidate runs hard on the "pardon all the J6 'political prisoners' platform" and get some traction. That said, they would only follow-through if it got them political points or some other personal gain.
I was going to say, coal remains around 1/3 of our electric generation worldwide (as of 2022): https://www.statista.com/statistics/269811/world-electricity-production-by-energy-source/
Coal can't be reused, created, or otherwise obtained outside of mining. Until we remove our dependency on coal, mining will continue.