Bumping this!!! After 3 years since OP posted this, it’s still annoying that there is no “system default” theme in the settings. I set up my computer to automatically change the theme to dark mode in the evening, but on the Roblox website you currently have to do it manually.
Even in the Creator Hub there is now an option for a system default theme (can be toggled here), and this is really needed on the main website & app as well.
