Why are open source software monocultures bad? The vast majority of non-Windows OSes are Linux based. Teams who don't like certain decisions of the mainline Linux team maintain their forks with the needed changes.

Manifest V3 is a great example of this. You can only backport for so long, especially when upstream is being adversarial to your changes. We need an unaffiliated engine that corrects the mistakes we made with KHTML/Webkit.

And we could get a functional one today by forking Chromium and never accepting a single upstream patch thereafter. I find it really hard to believe that starting a browser engine from scratch would require less labor. This is why I'm looking for an alternative motive. Someone mentioned licensing.

Perhaps some folks just want to do more work to write a new browser engine. After all Linus did just that, instead of forking the BSD kernel.