Earlier quoted context omitted.
That reminds me.. On macOS, the default application to open files with the .html extension is Safari, which I found is impossible to change. A tiny thing but it still makes me angry that someone at Apple intentionally removed my ability as a user.
You might want to check again. I just checked and mine is set to (and works with) Chrome. Right click an HTML file and click "Get Info". Then look for the "Open With:" section and select your prefered browser. Then click the "Change All.." button. I just tested this with `echo "Hello World" > test.html` and then double-clicked it in Finder and it opened in Chrome.
Apparently this was an issue with the user, not the OS. My bad.
EDIT: Actually, I remember now that I had to use duti to change this from the command line.