I don't really have a ton to say about them because I am bad at video games. I just despise the mechanic of Permadeath+Randomization. Everything about the genre screams "get good" while punishing all the central premises of learning. It's just random difficulty while feeding you semi-similar levels on the supposed "beginner levels". Every so often you'll have some bullshit happen that wipes all of your progress, with not a single save point in sight.
Look I'm playing games to have fun, not to feel like some super badass that has mastered every possible mechanic a game can throw at you based solely on the beginner levels. It just feels like the genre exists to punish you, rather than to foster enjoyment.
It can be configured to your liking, you can generate a world with every cataclysmic thing possible, or just slow zombies, or just wildlife and every point in between.
Plus you can make a very powerful starting character if you want to, with lots of skills and equipment, or a naked, hungover, sick character who was in the shower when the world ended.
The difficulty can be all over the place, which to me makes it immersive and fun.
I had one game where I was barely scraping by, running from most enemies and desperately trying to find any actual weapon that wasn't made of twigs and hope, then just stumbled upon a dead SWAT team, complete with body armour (slightly used), more guns and ammunition than i could carry, and an armoured SWAT van with half a tank of petrol.