Most browsers have consolidated over time because we are constantly updating web standards and bar for security is so high. On top of that everything has to be insanely backward compatible
WebGPU is a good example. Implementing that securely in a nightmare
There are lots of distos out there, but we all use the same core and make it better & safer together.
Coming from Enterprise Architecture world, if you're not already treating browsers as full-fledged operating systems to manage and secure, then you're operating dangerously. In fact, that's actually why I'm resistant to further "webification" of software and applications, as it's the same drawbacks as nested virtualization: now we have the OS layer that makes the computer run and the web browser layer to interact with stuff to worry about, both of which have their own performance penalties and threat profiles.
As much as I love REST APIs (and boy, do I love them and their simplicity), I don't like the idea of everything running a web server when it doesn't have to be.
What I was trying to say is that we only have a single kernel in the linux world without complaint, so having a single browser "kernel" (chromium) can be seen as a good thing. We have multiple distros (chrome, edge, brave, etc) for the browser as well
Hell, even Firefox could relatively easily swap to running on Blink since most of their UI these days is CSS+JS.