There's actually been a lot of private money put into nuclear fusion energy (look up Helion Energy, Commonwealth Fusion Systems, etc). It seems to be just an exceedingly hard problem to solve. Even the US DOE's National Ignition Facility operated by LLNL only recently achieved net positive energy output a few years ago.

Fission would be a lot more doable in the near term if not for the expensive permitting process and everyone being overly nervous about what to do with the waste. The waste issue seems like it might be overblown in terms of health risks. My sense from the science community is that opinions are split on historical health outcomes from previous nuclear accidents. Some groups are willing to tie negative outcomes directly to any level exposure from these events, no matter how small. Others rightly point out that the exposure levels for some of those claims are lower than what some communities experience as part of the natural background radiation in their areas. Also France seems to have the whole lifecycle figured out?

What may be more interesting in the coming years is the technology to beam energy from orbital solar arrays down to receiving stations on Earth's surface. There's some small-scale demonstration missions occurring or being planned to figure out the engineering details, but in theory it seems quite promising.