I think we will keep accelerating, but Fusion has taken so, so long to get to where we are now, every advancement has been met with a setback, and we still only have a few parts of it working on small scales.

The ones to watch for the next few years are ITER and CFETR for large scale tokamak style reactors, as well as SPARC for a much more compact solution that looks very promising as it can be built faster and cheaper. I don't really see inertial confinement or pinch reactors being the way forward for power generation, but you never know.

Generations are generally ~20 years. It's been 3-4 generations since the first nuclear power plant, and less since the first commercial one. It'll certainly be at least one more before commercial fusion even being optimistic

The problem is that fusion research does not tend to receive a lot of funding, especially relative to the huge challenges it presents. Even the National Ignition Facility, where this milestone was reached, was only built because it was needed for nuclear weapons research, with advances into using fusion for energy generation being essentially a side benefit (at least, from the perspective of its government funders).