I'm looking for a few eco or socialist related bands that fall on the Punk/Crust/Black Metal spectrum.

Martyrdöd is Swedish Crust with spices/traces of Black Metal.
The debut is great but wirh the 2nd record, they nailed it

Altar of Plagues debut is about manmade environmental collapse.

Big cosign on that Martyrdod album as well.

You mean something that is a mix of crust/punk/black metal or anything that falls in any of those genres?
Striborg of course comes to mind when it comes to eco-black metal. As far as socialist black metal, I don't know about that. Euronymous was a Communist apparently, and Varg has numerous times expressed contempt for Capitalism, but of course that isn't reflected in their music. Black metal tends to be very misanthropic and very anti-humanist--values that tend to go against those of socialism.

I don't know if being explicitly socialist is required to have your music uploaded on the Antifascist Black Metal Network, but it seems like a good place to look:

https://www.youtube.com/@AntifascistBlackMetalNetwork/videos


There's literally a band called Ecologist there, if that doesn't fit the bill...!