• Chromium-based browsers do not support user styles
• Chromium-based browsers can’t block data URI-based requests through the webRequest API.
• Chromium-based browsers are being “infested” by Instart Logic tech which works around blockers and worst, around browser privacy settings (they may start “infecting” Firefox eventually, but that is not happening now).
• I am not aware of any anti-fingerprinting initiative taken up with Chromium, unlike with Firefox.
• Etc.

There is much more I could list here. It baffles me that some people thinks Firefox is becoming a “Chrome clone”, it’s just not the case, it’s just plain silly to make such statement.