System fonts are fonts that come with the operating system (OS). Web developers and designers typically use them on their sites because they’re familiar to visitors (they match the OS) and they can improve rendering and site speed.
Weeks before Chrome 81 was released, Darryl Hein, a web application developer, discovered that the beta version of Chrome 81 could no longer bold system fonts on macOS. Hein was able to confirm his discovery by removing the system fonts –
system-ui,-apple-system,BlinkMacSystemFont – from the font stack, which reenabled the ability to bold text.
Several days later, the bug caught the attention of Adam Argyle, maker of VisBug and Chrome CSS Developer Advocate at Google. Argyle created a Chromium bug report, but the Chromium development team ultimately decided it wasn’t a blocker for releasing version 81. That resulted in sites like Coywolf not being able to use bold text for fonts that are larger than 16px (e.g., every heading).
The bug won’t be fixed in version 82 because the Chromium team announced that they’re skipping it, and will be releasing version 83 in mid-May instead. Argyle assured everyone on the original GitHub bug report that it would be fixed in version 83.
The bug is of very high priority internally and is marked as a Chrome 83 blocker, aka required for 83 releasing. While it may still reproduce in Canary, I’m confident 83 will include resolution.
He also offered a temporary solution and stated,
I’ve got projects affected by this too, and yeah, the Chromium team is on it.