Earlier quoted context omitted.
Did you have some plugins in vim? It is very odd if it was slower in this scenario.
Not to my knowledge, outside of whatever Debian comes with. Keep in mind this was on a Chromebook - so it would have been running in a VM on a rather memory restricted system. That said, VSCode would have been running in the same parameters. Just found the file. 42MB on a single line. Takes 5 seconds to open in vim, and about 3 seconds for the right arrow to move the cursor one char over. Nothing like gedit, but slow…
This makes a world of a difference when your editor is configured to wrap lines, or clip or w/e.
You probably happened to have VSCode configured to do something that mitigates the problems of having an extremely long single line, while Vim was not configured to do that.
In case you don't want to investigate the problem, but want to make a more "fair" comparison: use a language that you are comfortable with to format the file with linebreaks and indentation and then load it in different editors.