Recreational drugs are widely available

They do not work that way.

Depends on the drug, and the interpretation of "not striving for more": https://en.wikipedia.org/wiki/Amotivational_syndrome

Buddhism does, however.

I actually practice TMI. It works for me, at least to a degree.

It's not bad, it's just that if you were able to do this then you would not reproduce and would remove your contribution to the genetics (and to a lesser degree, memetics) of future generations.

That's not true though? Iguana's reproduce just fine. Being content with what one has does not preclude seeking out sex.

Totally agree with this. The iguanas have evolved to be able to totally subsist with what is in front of them and not strive for more. Their Maslow checklist is 100% complete :)

Yeah, but Iguanas don't post on HN.

I get what you are saying, but...What about the evolutionary advantage of another organism that strive for more? The moment exists competition you are force to struggle to survive.