I believe that most of the comments complaining about overspecing the runtime mentioned in this article (if at all, I find it reasonable), are extrapolating on their experience and referring to a general problem of overspecing in the industry.
1. Whenever I see a new company's/project's runtime, I have come to expect a massively overcomplicated system that is "built to scale". But ends up costing a lot and taking way too much time from product-development. A real issue with this is that when looking at the project's feasibility to actually do scale, the runtime-cost will be estimated to a multiple of the current runtime cost which will appear larger than if the systems were built to handle the current load.
2. To me, this seems like a failure of cloud computing, which has a very compelling promise of letting you start with small servers, then easily switch up to bigger servers when needed. This was, in fact, hard before cloud.
3. The biggest issue I have with overspeced and overly complex deployments, is that to me it appears like (novice) developers is led to believe that they have to do the job in a complicated way. Look at a typical tutorial from the big and trend-setting players how something should be deployed. The first hit on my favourite search engine for a "Hashicorp Vault deployment" [1] recommends using nine hosts. I know from experience that it runs fine on ONE host of the smallest kind I could find for our non-trivial use-case. Also, in that use-case it doesn't matter that it is not HA, because it has turned out to be more stable than any of our other stuff, and can be restarted in a less than a minute. (I wouldn't mind at all, if the actual motivation for a large deployment was: "it is fun this way" or "we do this for our own training and experience" or "we choose to do it this way because of specific requirements" or anything of the sort.)
4. It seems to me that, what is needed is enough experience and courage to say: let's do our deployment and setup in a simple way that will work, because we know that we are competent to solve scale issues when they appear and we are not building ourselves into a corner. Also, we can afford to take responsibility if scaling problems do occur because we did not follow industry "recommendations" (i.e. trends).
[1] https://learn.hashicorp.com/tutorials/vault/deployment-guide
Edit:
- clarified HA needs in point 3