A flaw in browsers & Gnome tweaks which doesn't recognize what "default" extensions have been forced deleted or doesn't exist anymore.
Except "Software-center" app, almost browsers (Chrome or Firefox) doesn't recognize which default extension has already been removed. Either the Gnome extension site doesn't function properly in any browser or something is fishy.
To prove this, these are some screenshots:
Chrome browser in extensions.gnome.org/local : https://imgur.com/v44Lhlc This is terminal output of: pranav@inspiron-5548:~/.local/share/gnome-shell/extensions$ ls https://imgur.com/FL1i9Nh
OS: Ubuntu 19.04.
I think this is common in all distros.
Edited by Pranav