In FOSS, community & volunteer made software, yes, there is onus on you as the user to do a bare minimum of effort. You have to meet the developers and the software where it is.

I very literally said “GUIs are better but harder to implement.” The second half of that sentence is not trivial.

If you want to customize and tweak things in the guts of a program (like OP does for this discussion), you can actually do it with FOSS applications. But expecting developers to expose every configurable option with a GUI would massively slow down the pace of development. Making them available in config files is a nice compromise between doing all that work and not exposing the option at all, in which case you’d need to actually patch the executable or otherwise modify the source code.

I’m not discouraging people from working on GUIs. I’m just pointing out the fact that if an app doesn’t expose a setting you want to change, your options are a) complain that the dev hasn’t implemented that, b) change it yourself which would be hugely easier if you looked the documentation, or c) find another app. Saying “the onus isn’t on me” doesn’t work when you don’t pay for the software and the person who wrote it is a volunteer, it just makes you an entitled asshole.