Sure, but solar won't be enough to power us forever, and doesn't scale like fusion eventually will.

We will have energy needs orders of magnitudes more than we do right now within the next 20 years. I'm all for solar, but fusion will be necessary just in terms of dealing with climate change and the energy needs that alone will bring with it. Carbon sequestration, water desalination, etc... are all going to need serious energy behind them and will be knocking on humanity's door before the 2050s.

The radioactive strength and decay time is not that long, right?

The nuclear waste problem is drastically overstated and, like almost every other aspect of nuclear power, is generally fear-mongered and cherry-picked as some sort of "gotcha".

https://www.energy.gov/ne/articles/5-fast-facts-about-spent-...

From the article: "the U.S. has produced roughly 83,000 metrics tons of used fuel since the 1950s—and all of it could fit on a single football field at a depth of less than 10 yards."

I'd be more comfortable with a nuclear waste storage facility in my area than I would be with a coal power plant polluting the same given area.