Why fonts are so pixelated all of the sudden in windows 10?
Looks like somehow ClearType got deactivated. ClearType is Microsoft’s implementation of anti-aliasing for fonts.
You can find the ClearType settings by searching for them on the start menu or by going to Control Panel → Appearance and Personalization → Fonts and then selecting “Adjust ClearType text” in the sidebar. They are not accessible from the Modern UI Settings app, except when searching.
Edge always has ClearType enabled, that’s why it wasn’t affected.