I mean… we all know why

because if they advocate for actual action and not performative theatre they'd not be elected, nor reelected. ehg who's going to vote for politcans banning cars (the IPCC has said multiple times that cars are the problem, not just the engine), banning flying, starting with private jets, a large tax on meat, banning advertising and on and on)

Can't remember who it was, Michel Barnier perhaps ? "We're all well aware of what needs to be done, we just haven't figured out how to be re-elected after we do it"

So, why aren't they advocating for performative climate theatre ? because they are aware there's less votes in it, regardless of what the polls say, the only important poll is an election. An example with socialized heath care, which is widely supported in polls, yet voters who often need it most still vote Republican anyway.