Ask HN: Why DevOps is still complicated in 2021?

Please point to my dark spot, because I really want to understand something. Aren't like ~90% of all web infra deployment usecases eventually come down to just "run N instances of my M apps on these L nodes, and make X of them available for incoming traffic (+ optionally create me few overlay networks inside cluster)"? With lower level details resolved on per container/app level. Why then k8s and all those tools make even simplest cases look so complicated? Why then tools following "simplify things" ideology (like Swarm) are barely surviving in the shadow of monsters like k8s and alike? Why aren't there widely popular tools that compete for simplicity with heroku? Do I miss some big point somewhere or people just really love to play with complicated solutions of "not so complicated" problems?