Climate predictions end in 2070, but the world does not. "We're fucked" isn't a reason to throw our hands up and not try.
Fusion is "too late" the same way every other decarbonization tool is too late. It doesn't matter. Do it anyway. In 200 years the people who threw up their hands will be seen as short-sighted.
People who wasted fortunes on dead ends will be seen in a rather worse light.
We already know what we need to stave off climate catastrophe: solar and wind, with storage and hydrogen synthesis, might be enough. Each cent pissed away on useless frivolity incrementally reduces our chance of success.
Nothing about fusion energy research indicates that it is a pointless frivolity. Things that fall in that category are adtech or fintech or middle management.
Fundamental plasma physics research is a boon. It might be worth all the spurious fusion work to get the plasma research, and continuous employment for the population of plasma physicists.
Fusion is "too late" the same way every other decarbonization tool is too late. It doesn't matter. Do it anyway. In 200 years the people who threw up their hands will be seen as short-sighted.