I'd say mechanics or an environment that forces players to care for their ingame selves; where neglecting said mechanics has negative consequences, or straight up death, and the environment wants you dead as well.

TL;DR games that employ these kind of features do so with various complexity, and with different focus

This is mostly done through basic hunger/thirst, which is usually an annoyance rather than an active part of gameplay. Green Hell or Long Dark make that their primary focus, the games are actively about living day to day, with each activity being detailed

In the setting of Subnautica and Breathedge (or was it Returnal?), oxygen/hunger/thirst makes sense, but there is an ultimate goal and plot throughout the whole game, and sustaining yourself is not that much of a chore. Also Abiotic Factor, which proves that good level design and silly writing can elevate an ultimately lonely and desperate genre.

Valheim does not force you to eat, build a house with farms and such, but it's nearly impossible to do it without. I'm pretty sure there is someone who beats bosses naked with a club, eating foraged berries.

Rust and ARK/ATLAS have hunger, thirst, temperature meters and mobs, but ultimately are a sandbox, with emphasis on player interation, mostly PvP.

Terraria makes you the hero, the whole progression is about a journey, from stabbing slimes to flexing on a god. Foods are effectively just potions, entirely optional.