Do the simplest thing that could possibly work

I appreciate the sentiment, and absolutely think it should be kept in mind more.

But of course, it runs afoul of reality a lot of the time.

I recently got annoyed that the Windows Task scheduler just sometimes... Doesn't fucking work. Tasks don't run, and you get a crazy mystery error code. Never seen anything like it. Drives me nuts. Goddamned Microsoft making broken shit!

I mostly write Powershell scripts for automating my system, so I figure I'll make a task scheduler which uses the C# PSHost to run the scripts, and keep the task configuration in a SQLite database. Use a simple tray app with a windows form and EFCore for SQLite to read and write the task configuration. Didn't take too long, works great. I am again happy, and even get better logging out of failure conditions, since I can trap the whole error stream instead of an exit code.

My wife is starting a business, and I start to think about using the business to also have a software business piece to it. Maybe use the task scheduler as a component in a larger suite of remote management stuff for my wife's business which we sell to similar businesses.

Well. For it to be ready, it's got to be reliable and secure. Have to implement some checks to wait if the database is locked, no biggie. Oh, but what happens if another user running the tray icon somehow can lock the database, I've got to work out how to notify the other user that the database is locked... Also now tasks need to support running as a different user than the service is running under. Now I have to store those credentials somewhere, because they can't go into the SQLite DB. DPAPI stores keys in the user profile, so all this means now I have to implement support for alternative users in the installer (and do so securely, again with the DPAPI, storing the service's credentials).

I've just added a lot of complexity to what should be a pretty simple application, and with it some failure modes. Paying customers want new features, which add more complexity and more concern cases.

This is normal software entropy, and to some extent it's unavoidable.

Had to make an account for this, but this is almost verbatim what the article is talking about:

Your wife is making a business, and you want to write some code to help.

Then suddenly your requirements balloon to multiple concurrent users, needing to have a system tray icon and then also the ability to take this code and sell it to other people. Wow this project is suddenly complex!

This is just "I need to be able to scale infinitely" written in different words. The complexity comes from wanting a ton of things before they're actually needed (with the wrinkle of wanting to use some previously written scheduler for this project.