I think the main thing with Chrome/Chromium was the browser's lack of a GUI for enabling the pkcs11 plugin your smartcard reader, necessitating the use of the

I think the main thing with Chrome/Chromium was the browser's lack of a GUI for enabling the pkcs11 plugin your smartcard reader, necessitating the use of the modutil CLI. Firefox has this in the GUI (settings -> privacy and security -> security devices).