I used to use ansible and helm, but it is overkill for my case. Today I basically use a combo of markdown and bash scripts, the combination of them allows me to run the scripts straight from my IDE.

I had the same idea a couple years back and even though I would love something that you download and just run and it would work, I realized that in order to get a decent adoption rate, you would need a whole ecosystem, similar to apple in order for it to work.

I still think you can develop something like a hub where you install services like apps, but I doubt it would attract anyone outside selfhosting circles.

There are several things you can and should do to harden your server, many of them can be found here.

What distro are you using? I update on a weekly basis and usually have 10 - 15 updated packages.