According to this Vivaldi protects you from tracking about the same as Chrome and Opera, and both of those provide less tracking protection than even Edge.
Chrome is run by a massive corporation with a reputation for for invasions of privacy. Opera is run by a nation state with a reputation for invasions of privacy.
Firefox already has containers. I still have yet to see a browser that beats stock Firefox in functionality, customization and privacy
I’d venture out there and say Vivaldi in functionality and customisation.
Privacy probably not, though Vivaldi does quite well.
Sadly it’s a Chromium browser.
Edit: a simple comparison.
According to this Vivaldi protects you from tracking about the same as Chrome and Opera, and both of those provide less tracking protection than even Edge.
Chrome is run by a massive corporation with a reputation for for invasions of privacy. Opera is run by a nation state with a reputation for invasions of privacy.
Vivaldi is far better than either of those.