There is a new browser (non-open-source) named Psylo that describes itself as:
We’re super excited to finally launch Psylo, a new kind of private web browser for iOS and iPadOS. In Psylo, each tab is its own silo with isolated storage, cookies, and even its own IP address. Psylo introduces advanced anti-tracking and anti-fingerprinting features that go beyond what a VPN can offer, thanks to the deep integration between Psylo and our own Mysk Private Proxy Network. Psylo is backed by years of insights from our privacy research at Mysk. Psylo is available today on the App Store as a monthly or annual subscription with a free 3-day trial.
This is an interesting architecture. While it may be a departure from what Firefox provides, I think the essential design is not proprietary and is useful. Firefox could do this, potentially monetize on a VPN/Proxy subscription, but people should be able to use their own.
But, migrating to a model like this would likely require users to start over with any long-term cookies (login, auth) that they have stored.
It’s an interesting design, I wonder if Firefox might consider something along these lines.