If yours is a massive company with resources to run separate centralised infrastructure for secrets management, sure. There are other nicer tools too - Doppler comes to mind.

I just wanted to build the simplest possible thing that would achieve the functionality.

I like how what you created lets you load variables into your system easily. Have you checked out Doppler Share? https://share.doppler.com/ It might be useful if you didn't want to use the command line for similar functionality.

Requires you to trust Doppler's servers to be secure enough. But I guess that is a given with Doppler overall. Definitely useful though!