Starvation doesn't unlock

Tartarith doesn’t give this punishment anymore, though it’s still usable in old saves.

You need to be deified with all 15 gods and have all the blood altar upgrades unlocked.

Is this a new thing or was it always like this?

It was always like this - it’s the most difficult to unlock because it’s not meant to really be a go-to feature. I didn’t like how it turned out but figured some people might have fun with it anyway.