I am not. GP doesn’t mention running managed. When talking about “basically free” and for side-projects I don’t really get your point. Minimum cost for a one-node n1-standard-1 cluster is a subsidized ~25 USD per month on GKE (assuming not using preembtibles). After 1 year you’re above the price of comparable hardware (there are pretty decent 300 $ laptops these days).

I’m a happy customer of GKE but it’s not for everyone and everything. Like you say, different use-cases.