Text is italic in Chrome, Firefox and VS Code

There is usually an app for changing font settings in distros that can have fonts other than sans-serif or something else that looks familiar. Just search "fonts" in the app search bar and play with some settings until you find a font that looks better. (I don't have screenshots or anything because I use Ubuntu Mate so I have no idea what exactly the steps are, but they are usually almost identical on all distros, including non Ubuntu-based ones).