History feels like the only part of Firefox that is still stuck somewhere in the late noughties. They should just copy what Chrome and Safari have done and make it a webpage instead of a separate window.
Honestly, I haven't found browser history to be useful anymore. Not in 6 or 7 years. Too many sites are SPAs with server-side state, breaking the back button, breaking multiple open tabs in the same application, or breaking both.
Slight correction with Safari, it uses a native NSOutlineView rather than a webpage, but the point that history works better in the main browser window stands.