I don't see why the author is so proud of avoiding tooling that would make their build and deploy process simpler? Even something like digitalocean's own buildkit based "apps" would be an upgrade here. Deploying your app using ssh and git is not magic or simple it's just a refusal to learn how actual software delivery is done.
Even totally dodging docker/k8s/nomad/dagger or anything that's even remotely complicated platforms like AWS/DO/Fly.io/Render/Railway/etc obsolete this "simple" approach with nothing but a config file.
I also theorize that the author is likely wasting a boatload of money serving ~0 requests on the staging machine almost all the time, due to him literally switching a floating IP rather than using two distinctly specced machines for production and staging
I disagree, avoid CI/CD tools is the right call until this grows enough that you can't continue writing small scripts. I think all the CI/CD tools are garbage in that by being generic they do a poor job at addressing your specific needs.
I don't know who needs to hear this, but you don't always need to start a project by reaching for the most complex tool possible. Build up to it and then you won't need convincing to use it.
Alternatively, learn how CI/CD works and have a comprehensive tool in your toolbox basically forever
Are there any CI/CD tools that are likely to stand the test of time in the same way the basic unix ones have?
I'm not against making things easier. But I feel like it's so easy to over-engineer and rely on proprietary crapware.
Is there a conservative path forward here?
No, they are all horrible monstrosities. The ones that are hosted by others (github actions) are still monstrosities, only that other people are taming the monsters.
The best way I've found is to keep the CI/CD tools as just simple task runners. They should only have to figure out when to run things, inject the necessary environment(and secrets), and figure out dependencies (if applicable) and run those. Whatever they run, you should be able to run the same scripts from your own laptop or a similar.