I read through the thread linked above. You are confusing "conservationism" with "conservative" Like we have to conserve, and so we should be "conservative". Not a terrible mix up.

In any case, the debate on the left is:

Planned degrowth vs. Eco-modernism.

And I think it is correct to prefer a strategy of conservationism, that is degrowth, vs " keep building "productivity" which is eco-modernism.

If in fact you are more attracted to the degrowth model, look into Jason Hickel. if you wanna research the other side, or feel affinity toward eco-modernism, you might check out Leigh Phillips. Here's a primer for the debate.