Hi author here. If you are using GitHub, I can't see why you would not want to use Actions, in which can they are all "hand rolled", you could abstract a lot within a custom action, but that is just another black box (which was not the point of the post). The use of GitOps doesn't make a whole lot of sense in the situation where 1 VM hosts everything you need. 4 lines of .env is not a lot, and more would be the apps concerns. The compose files let you run your system locally with very standard tooling. Finally, the "bash spaghetti" is using tools like SCP/SSH, which as said in the video are well worth learning, and are going to work the same way now than in decades time. It is hard to say the same for present day K8 tooling. Docker compose tools while not as stable, again, I think will remain relatively stable in comparison.
Granted, Kubernetes is super powerful, and if you are managing a large team or teams infra, by all means it can make a lot of sense. However, there is a large amount of systems that just never need that kind of scale where the Kubernetes benefits start materializing, and meanwhile cost of managing the cluster(s) is there from day one.
Each to their own, it was just a way of showing those who might not be familiar with common tooling a "look behind the curtain" as it were.