First point is not relevant, fusion has been chronically underfunded for far too long. The money being spent on fusion r&d is far less than the money going to renewables deployment, and you advocate cannabilizing even that???
I won't go down the list of how many technical contributions are coming out of fusion, just know that there are a lot, that help make both renewables and non-renewable more efficient. How do you switch tremendous amounts of current at extreme voltages, very quickly? The answer directly impacts overall efficiency of everything from EVs to micro & macro-grids. Usually it's a pick-two-of-the-three, but switch systems are being used to solve these exact issues, successfully.
As for why I'm hostile? Read the previous two paragraphs again, maybe something will jump out at you.