It will take several decades for any new energy solution to replace fossil fuels across the globe. Doesn't matter if its PV, Wind, Hydrogen Boron or some mythical cold fusion. In a decade PV and batteries will be even cheaper and more efficient with the added benefit of having decades of market acceptance. LPP is at least a decade away from having a marketable product, and that's always been the deal with fusion, its always a decade away. Still, best case lets say they get a working, profitable reactor by then. They still have to deal with getting regulatory approval, and more importantly acceptance by the general populace. The NIMBYers will prevent any sort of nuclear reactor (Fission, Fusion, safe or unsafe) from being installed anywhere (at least in the US) quickly. By the time enough of these reactors are online to matter PV could have already completely replaced fossil fuels.
In the grand scheme of things a few million isn't significant enough to matter, but its going to take real money to get these to market, and that's not worth doing.
Your points are mostly logical and supportable, so reasonable people can disagree.
However, while obstacles for any course of disruptive change can be foreseen, obstacles are meant to be solved or minimized by creativity, hard work, unforeseen add'l tech discoveries and motivation by deep pocket corporations eager to make massive profits from the disruption. If Elon Musk and his lieutenants had looked at all the obstacles to bringing great EVs to market and threatening the huge ICE companies, blinked and not tried, where would EV progress be now?
That difficulties would attend fusion success is no reason to not fund research into promising alternate approaches that cost a pittance compared to what's being wasted on approaches doomed to economic failure.