K8s is complex. For this reason Cloud providers sell it as a service. K8s and microservices are a trend topic, so it is true you must think with your own head before creating microservices at will.

But I think the article is a bit too negative.

For instance, in my humble experience the application server is always a bottleneck before the database (i.e. if the database is Oracle or PostgreSQL).

Microservices move a bit of complexity on the client side, ask for smarter clients and offer a lot more resilience and fault tolerance.

The article focus only on scaling and forget the "Single Point of Failure" problem.