Yes. I see chromium as the linux kernel. Piece of fundamental infrastructure that does the the heavy lifting and one can reconfigure, tweak, add features or eventually fork if needed. Never been easier to build an independent browser.
We need independent groups of passionate people making sure that the web platform is focused on the best end user experience. We don't always have that today, but that vision is completely dead if the web functionality is decided entirely by an advertising platform.
The browser engine is open source. You can make changes and proposals with your own fork. If you are making a browser for musicians you could try and advance the WebMIDI spec and add new functionality to it and then try to get it standardized. But as a browser developer you don't want to me spending your time implenting specs that other people have already implemented, but rather spending time working on things that improve your browser for your userbase.
What would be the point of open specifications if there was only a single implementation?
I never said there was? When you write the first implementation then there will only be a single implementation, but that's how counting works. 1 comes after 0. Anyone is free to write another implementation.
A robust and reusable browser engine lowers the barrier of entry for anyone to innovate and differentiate. Browser compatibility is close to solved since everyone shares most of the implementation. Better user experience across the board at lower cost.
Specific examples are Brave, Opera, or more recently the Meta Browser shipping in the Meta Quest: very small team now leading the WebXR standard. it wouldn’t be possible without Chromium.