I think it takes up too much screen real estate, and doesn’t add anything to the view.
- Right- click on menubar, select “customize toolbar”, select " titlebar" on left bottom. See here: https://www.reddit.com/r/kde/comments/udvxje/why_are_the_window_decorations_for_firefox/ 
- I think there is an option if you right click the toolbar and the go to customize toolbar - https://www.geeksforgeeks.org/techtips/customize-toolbar-firefox/ - Well it’s not just Firefox, it’s all windows. - Idk about Mint in particular. There’s a way to do this in most de/wm. I would start in the system settings where you can choose light/dark themes. Then just go top to bottom in the system settings. - Sorry I couldn’t help more - Edit: If you don’t go through settings systematically like this often, it’s good practice. You always find things you’ll use later. 
 
 
- Search for ‘Extensions’ in the menu and download Cinnamon Maximus - deleted by creator - Pretty sure damn near every Linux DE has an extensions feature. - I’m not complaining about extensions but about “extension to remove”. 
 
- I have done that so much more on linux than I did on Windows, lol. It is the Linux way of thinking. 
 
 
- Right click on tab bar > click on last entry there (forgot how it’s called) and finally uncheck second entry from bottom left. 
- Switch to dwm. https://dwm.suckless.org/ - Ah yes, the ever growing and maintained X11 window system. - The future of security and standardization, with the mostly used feature of transmitting GUI assets over a network. - And to top it all off - the most documented code project, with the users facing easy customization options, that requires almost no programming language knowledge - and the easily compatible feature matrix, with allways up to date patch files. - I honestly know nothing about X11 but this reads like sarcasm to me, is it? - Extreme sarcasm. The Free Desktop organization essentially stopped all development of their old GUI solution for Linux - named X11 Window System, and went all in on developing Wayland, the successor. - Plus, speaking as a former DWM and suckless tools user, it is elitist, and thinks way too highly of themselves - they think their code explains itself (which it doesn’t), features are easy to add (nope), and a readable config file is bloat (it isn’t). - I started using dwm for the very reason OP asked. I wanted to remove the window decoration, have a more simplified view, and have full control over what my windows looked like. It works for exactly what I needed/wanted. 
 
 
 
 





