The renewables buildout was always tightly coupled with the nuclear phaseout in the political discourse.

The idea that you could've kept nuclear, still have the renewables buildout and close coal early wasn't a political position anyone in any relevant position was advocating for.

The slower phaseout of coal is about employment and, to a lesser degree, regional "identity" issues far more than energy.

The coal industry was at some point the country's largest. It's also older than all other in the industrial sector, since coal was the raw material fueling the industrial revolution.

As such, it became the raison d'etre for whole regions. The Ruhr area in west Germany grew from Iowa-level population density to New York State levels on coal. Unions, as a concept, got started in the coal mines. I recently saw a bunch of news broadcasts from the late 80s/early 90s and among 10 of them, eight or so featured labor issues in the sector. Until reunification, it was the most salient issue in politics.

It was right after the Fukushima disaster which was a last straw. Press coverage of nuclear energy by then was mostly negative thanks to Greenpeace and their campaigns against disposal of nuclear waste, history of Chernobyl explosion was still fresh, so politically keeping nuclear afloat was a risk. And of course, when calculating the real costs (i.e. including long-term nuclear waste storage and monitoring) it appeared not so attractive option to keep it.

There was no significant public will or movement to get out of coal 10 years ago. It was never even discussed.

Wind and solar are cheaper than nuclear. There is no solution yet to the final deposition of nuclear waste.