There's two main benefits to nuclear:
1) The big case is the lack of good power storage. While areas like the South West US have plenty of sunshine to go around, most other places don't have this luxury. Therefore you need substantially more storage. I'll give you an example, I've been sitting in Oregon for the past week and sun levels have been pretty abysmal, the past week. Dust and ash are covering panels, making things worse, and this is the sunniest time of the year. There's plenty of times I don't see the sun for a few days straight. Same with wind. Because of this we need to mix up our power sources a bit. I mean you also don't want to depend on only two power sources. I think most of us in the nuclear community agree on: wind + solar + hydro + nuclear as the model. Without good enough batteries nuclear is a great option for baseloads. Remember that you need enough battery storage for rare events where there isn't much sun and wind. Current solutions aren't quite there yet without massive footprints, CO2eq costs, and a high price tag. The unfortunate fact is that wind and solar can't stand up by themselves. They need support. People talk about how you can do it with batteries, water storage, whatever, but until it is implemented I'm not holding my breath.
2) Nuclear has a small physical footprint. This means less disruption of local wildlife, homes, etc. This is a big environmental factor to me.
As to what these people are doing, there's a few factors they are banking on (bets). It'll be interesting to see how that pans out and if their bets can pay off.
- With small modular designs they can get the benefits from economies of scale. This hasn't ever really been a thing for nuclear in the past. This has been a big driver for the huge costs.
- Small reactors should be cheaper to insure (this still needs to be resolved from what I'm aware of and has historically made small reactors unattractive).
- Small and modular enables the ability to better fit the local environment and meet the specific needs. Southern California? Probably don't need any. Alaska? Few would be nice. The idea behind these is that you don't have to transmit energy far (lower loss due to transmission), can add independence from the grid (to corporations or universities), and you don't need to put them in areas that can better rely on wind and solar, i.e. better scaling than conventional nuclear plants.
Of course, this is still a bet and has been one people have been talking about for well over a decade, but why dismiss it before they place their chips? If the bets pay off we should welcome them with open arms. If they don't pay off, well we're on a forum hosted by a startup company where we all know most startups fail. Glad someone at least tried. We're not talking about enough investment money that it would sway the scales and it is good to spread out your bets.