Deliberately making bitcoin worse would incentivize users to switch to alternatives like Libra or Ethereum (which claims to be moving to proof-of-stake).

An alternative could be where a coin could be directly proportional to a tree planted! Its value would go up as the tree grew bigger. Think of a carbon sink. While it would come with its own loopholes like having invasive plants. Its an interesting way to have an alternate. One could even expand to other similar sources which could aid to a better future.

Have a look at Cardano Ouroboros: "An environmentally sustainable, verifiably secure proof-of-stake protocol with rigorous security guarantees."

Do destroy Bitcoin, to incent people to move to more efficient alternatives.

Bitcoin should have died a decade ago.