hpst I used to read a lot about configuring font in Linux, but I'm not currently on Linux today so I can't give advice on an optimal Linux configuration because it's always changing. I can however mention, that you also need to pay attention to whether the bytecode interpreter is on or off for any given font being rendered by freetype. The ebook reader I use lets me toggle it on and off, and the preferred font I have for books looks way better with bytecode turned off than on. I think there is a FF config to respect the system setting, but I am not sure. The classic web-safe fonts you mention, I know them well. They are a set of fonts Microsoft released to the public a long time ago to help make sure people had the same fonts on their computer so webpages would display better. Anyway, these old fonts were all designed in an era of low-resolution screens, so they work great with anti-aliasing turned off, and they were also designed to work with bytecode rendering on, if you did alias them. Arial, Verdana, Tahoma, etc. Try them out, open a terminal window and type this:
sudo apt install ttf-mscorefonts-installer