Yes, use boring technology, I'm all for that.

But an application built in the high pressure environment of a startup also has the risk of becoming unmanageable, one or two years in. And to the extent you already have familiar tools to manage this complexity, I vote for using them. If you can divide and conquer your application complexity into a few different services, and you are already experienced in an appropriate application framework, that may not be such a bad choice. It helps focus on just one part of the application, and have multiple people work on the separate parts without stepping on each other.

I personally don't think that should include k8s. But ECS/Fargate with a simple build pipeline, all for that. "Complex" is the operative word in the article's title.