Shin Sekai Yori is great. It gets uncomfortable, but worth a watch.

Grimgar of Fantasy and Ash (Hai to Gensou no Grimgar) is another hard hitting isekai. A group of kids are transported for no reason or purpose, and with no special powers, and have to learn to survive in their new world. The story isn't completed in the anime (although ends at a good spot), so you'll have to read the rest if you want to finish it.

Shin Sekai Yori is great. It gets uncomfortable, but worth a watch.

Grimgar of Fantasy and Ash (Hai to Gensou no Grimgar) is another hard hitting isekai. A group of kids are transported for no reason or purpose, and with no special powers, and have to learn to survive in their new world.