The problem is that most people do care about the environment but are hopelessly misinformed about what to do about it.

They think that personal acts of minor inconvenience like tolerating soggy paper straws saves the environment while fighting things that actually make a difference, like blocking transit to save a nest of bats; or blocking urban development to provide an extra 3 minutes a day of sunlight on a surface parking lot; or that somehow them flying across the USA to visit a national park and connect with nature or something is offset ecologically by token actions like reducing how many plastic grocery bags they use throughout the year. Most ordinarily people don’t understand the tradeoffs of their choices in the slightest.

And on top of that culture wars and geopolitics is getting in the way of progress - we could be blanketing the world in solar panels and batteries and EVs on the cheap right now, but it’s dominated by enemy #1, China, so we won’t; not to mention that the right in the USA seems to think that renewables are for girly sissies. And the alternatives we have, like nuclear power, are being shut down across EU countries because people have no idea of just how self sabotaging that action is, given that the alternative is going to be fossil fuels coming from Russia and the Middle East. They’d rather die of heat stroke than use energy efficient air conditioning, so the powers of most people’s imagination are shockingly weak.

Popular opinion wants to blame everything on capitalism when the reasons for these problems don’t actually stem from there. Capitalism will be the way out if it’s given the chance, but it’s not popular to say that, so it won’t.