Ubuntu 23.04 and later comes with new slim font for the text in system menus, documents, and app windows. The new font is slim and hard to focus. If you don’t like it and prefer the old font, then you can install the old Ubuntu system font easily in your system.
Install Classic Ubuntu Font [Ubuntu 23.10 & Later]
To install old classic Ubuntu font, open the terminal application (ctrl+alt+t) and run below commands. It will install it via the system repository.
sudo apt update
sudo apt install fonts-ubuntu-classic
After the installation, you don’t need to restart. It automatically change system font to old classic. For the better result just restart your system.
How to restore System Default Fonts in Ubuntu:
To restore the system default fonts, just run the below command in the terminal.
sudo apt install fonts-ubuntu fonts-ubuntu-console