In term of time to patch 0-day, Firefox is very quick to fix them (usually hours committed, days to publish). Chrome is quick too, so it's not a competitive advantage.
Most of cyber-criminals however, will target Chrome because it's way more used.
In term of control the password manager of firefox don't need you to have an account. That is very important because, you want to use a password manager on the web and to be able to actually trust it. Google can close you account without previous notice.
Privacy aside, Google controlling so many parts of your life if you're all-in on the ecosystem is insane, and they can nuke it all at a whim with no recourse possible.
I was using Google Workspace for my family, then realised that if Google decided to nuke my account I would lose so much, and migrated away from Google's services to individual ones instead. Fastmail for mail, Tresorit/Dropbox for cloud storage, iCloud (with backup) for photos, etc.
Sure, you're still at risk if a company nukes an account but you'd not lose your whole online life.
Most of cyber-criminals however, will target Chrome because it's way more used.
In term of control the password manager of firefox don't need you to have an account. That is very important because, you want to use a password manager on the web and to be able to actually trust it. Google can close you account without previous notice.