Don't be ridiculous. To the nearest 9 decimal points, nobody keeps their mission critical database inside Kubernetes, and the K8s tax is excessive for essentially all cloud users anyway.
I think for that particular firm, "K8s tax" measured in fiat currency is negligible and anything on the human side their people upon hearing "K8s tax" would respond with some ridicule along the lines of "someone doesn't know how to computer".
To be fair, most of the commenters on HackerNews should use something like Heroku.