It's just a bad list. It includes hosted Kubernetes solutions, application unrelated to Kubernetes (which may run on top, think Postgres), deployment options, built-in metrics, and lots of other random things. It's as if someone googled Kubernetes and copy & pasted and first 20 pages without any understanding or theme. This looks like some PR person hired a a low-cost freelance writer to "write something about Kubernetes because it's hot and we need traffic, deliver it tomorrow" - It's like someone writing "50+ useful Python packages" and just listing 50 completely random packages.

I've been operating Kubernetes clusters for years now, and most of these are completely irrelevant to me, dead, or I've never heard of them. Don't equate bad lists with complexity.