Fusion plants produce exactly zero electrical power. Someday they might. They don't now. The complaint was that we shouldn't talk about the cost of developing fusion power because someday it might be magic. But it's not magic, and the cost is non-zero.
And the relevant competitors aren't coal (which is already dying), it's things like solar and wind, which are already available, somewhat cheaper than coal on balance (but not gas, yet), and literally infinitely cheaper than fusion.
I'm not saying that fusion is a bad idea, but you can't shut down discussion about its very significant costs with a fairy wand and some text about improving the human condition.
Fusion power has been just around the corner for literally three quarters of a century. It's time to start prioritizing the thing that have actual, measurable effects on the human condition.
Fusion plants, on the other hand, produce only electric power.
If fusion could be figured out, we could use 10x as much energy as we do now with no long-term environmental consequences. That would do a great deal to improve the human condition.