Linux user with no care for Mac features. Firefox may be open source, but Mozilla is a company with a paid development team. It is exactly these types of issue

Linux user with no care for Mac features. Firefox may be open source, but Mozilla is a company with a paid development team. It is exactly these types of issues - UX, UI - on which the dev team should be working. I'm sure that a lot of features come from the open source community, but the polish and sound implementation is on the dev team. For what it's worth, Firefox on KDE is fine.