Sods law will say if you don't invest in nuclear, you'll be using a lot more CCGT because storage or large-geography interconnects won't be there
But if you do invest, you'll end up being stuck with something costing far more than commodity renewables+storage
We have "workable fission" now, it's just very expensive. Workable fusion is always a generation away.
It does feel like Tokamak will never arrive. An acquaintance did their doctorate last year on modelling some aspect of the containment; they didn't seem hopeful.
If you go to https://model.energy/ and optimize such systems in various places, using real weather data, you find nuclear (called "Dispatchable 2" in the advanced options) get optimized to 0%. It's just too expensive. That site uses plausible cost numbers, except electrolysers are already cheaper than their target cost for 2030.
Battery storage is possibly going to fit in there, but it doesn't do it yet.
Tidal, ground source, gravity/momentum/compression/latent-heat storage solutions, some of these might do.
I think we need at least one more cycle of Nuclear power plants.
Perhaps then we'll have workable fission.