To me the worst case is trying to develop some small utility like a tool to search in files using regex. Because if you are developing something large, the amount of time you spend dealing with packaging, distribution, etc., is small and you don't care about file sizes.
But if I want to, say, develop the app for Windows. That is easy. You get a tiny binary to just opens a form and runs with a double click. No install necessary.
The same thing on Linux? Impossible. There is no guarantee the machine has any version of GTK or Qt installed at all, so to be self-contained you need to ship the entire OS. Now your file size is huge. I can't use Python, because now Windows users need to have Python or I have to ship an interpreter.
The only plausible alternative is something like Java. Now you have a single .jar file that runs on any system. But then Oracle changed the license, and JavaFX is no longer part of Java (Swing still is).
Honestly, I just want to display a menubar with keyboard shortcuts. Why can't there be a menubar VM or something that gives me access to a menubar on all OS's without having to deal with all of this. We are already shipping the entire browser with Electron. That is stupid. The way it should work is users install a something like Flash but for desktop apps and every app just uses that platform.
It's probably easier to ship a DOS game than a desktop app because everyone who wants to run a DOS game will just have a DOS emulator installed.