I believe that it's a physical plant thing. We have spent over a hundred years building hydrocarbon-based energy infrastructure. Much of that is still out there. Wind and solar have made a ton of progress in the last 15 years or so, but it's only really become substantially better financially in the last 5 or so years maybe. It's still going to take decades to actually replace most of that stuff, just as a matter of how fast we can build and install hardware.
Note also that it's a worldwide chart, so it includes developing countries that may not be so quick to jump on projects that are expensive right now even though they'll save a bunch of money in the long term. Though to be fair, some may have a leapfrog effect when it comes to building brand new infrastructure.
> a hundred years building hydrocarbon-based energy infrastructure
One consequence of that is the enormous of amount of scrap steel that will become available as that infrastructure becomes obsolete. It will noticeably perturb the world steel industry.
The amount of steel in a refinery is tiny compared to what the world uses. Even if we could scrap them all in single day (as if it wouldn't take months to tear it down) it is a drop in the bucket of recycled iron.
I would like to think that the switch to renewables is inevitable, but could a continuous series of administrations similar to the current US admin be enough to curtail it?
Seems unlikely to me. I always thought the only engine that could actually accomplish transition was capitalism. We will transition at a time and to an extent that renewables are actually cheaper and better, no sooner and no later. Government action can encourage technological development, but it can't force the transition when the technology is not ready yet, and it can't stop it either once it's actually better. Note that we are actively building out a lot of that stuff now, even though the current administration is at best indifferent towards it. It all fits with the bottom line that we transition when the technology is ready, and the opinion of activists and Government officials isn't relevant.