I think as soon as something becomes political, the factual arguments get lost (or at least more open to opinion-based massaging).
My dad is retired now, but he was an engineer working on various renewable tech since the early 1960s. So it’s not true that no one did anything. Dad was working on wind, solar and tidal power generation, nuclear (which looked like being the big leap forward until Chernobyl happened), brake energy regeneration, synthetic fuels and mass transportation initiatives for decades. Some of this stuff has become mainstream — look at wind farms (esp in Scotland), solar panels on houses, brake energy recouping and ethanol content fuels for example.
His view at the moment is that while there continues to be a pressing problem, the current XR-esque durm und strang semantics is itself political, and divides as much as it unites. And individual action in developed countries — most of whom are already reducing their impact — is largely tinkering around the edges. Shaming a couple in the UK for having a second child, for example, is pointless when there are millions of 12-year-old girls in developing countries being ‘married’ off to elders and repeatedly made to bear up to a dozen children through rape.
For him, the two big issues are reducing reliance on oil-producing countries in the Middle East, and the emancipation of women in the developing world.
But all global issues are interconnected, and massively complex, and there is no easy fix.
Ultimately the world just needs fewer people, and that will either be achieved through our actions or nature’s.