I coincidentally just made a joke about this, but Tor (which is based on Firefox) is likely safer than any of the browsers mentioned thus far. But it's completely inconvenient. And slow. Or better yet, connect to a VPN with good security features, and then use Tor (which would be slower still).
So you raise an interesting question: Which of the "normal" browsers gives the best privacy protection? I don't know the answer to that (and I'm not sure if anyone here would know that either).
I do know that Apple's privacy
policies are far better than Google's, but that's just about what data Apple vs. Google collect. it doesn't address the question of what data the sites you visit can collect.
You can find various articles ranking browsers for privacy. Here's two of them. As they come from companies that host VPNs, the authors should have some privacy expertise. But their rankings are not the same, and none of these are exactly from peer-reviewed journals:
Websites, advertisers, ISPs, and government agencies track every click you make. Check the list below to choose the best browser for privacy.
nordvpn.com
Discover the 15 best browsers for privacy in 2025. We review the best anonymous browsers for secure, private browsing on PC, Mac, Android, iOS.
www.expressvpn.com
The one browser I'd definitely avoid is Opera, since it's owned by a company based in the PRC, a country essentially entirely without privacy protections.