So by that definition you would only want one web browser as there are currently multiple HTML+CSS+JavaScript "front ends". In which case, you end up with a Chrome monopoly where Google gets to decide what the web looks like!
It's not plausible that that will that a similar entity will take over the HTML/CSS/JS space, because of the amount of money competing with users interests in the space due to things like advertising, the desire to invade users privacy, etc. Still, if somehow we could magic up this monopolizing organization without conflicts of interest that would be far superior to the current state of affairs...
The Rust community rationalization that they don't need / want alternatives for "reason" is self-serving and all about control. I don't care if someone is the BDFL, they aren't right 100% of the time and not always doing things for altruistic reasons. The Rust community has imbued the leadership with some godlike omniscience and altruism because it makes them feel good, not because it's sound policy.
Of course rust leadership is going to make and has made mistakes, I'm confident every BDFL ever has also made and will continue to make mistakes, the same goes for the 'herd' of clang/gcc/msvc/... and the herd of browser makers. The target is not perfection, but merely being better than the alternative.
I think that, in the absence of conflicts of interests, single source of truth models (e.g. what rust rust/python/java/... does) are likely to do better than 'herd' of competing implementation models (C/C++/javascript) at making a good language. The latter probably does better at working despite conflicts of interest, but that's not a problem with most programming languages where there is relatively (compared to the browser ecosystem) little opportunity for a powerful corporation to push their interest to the detriment of others.
I think the rust community is quite clear that the rust leadership is flawed, but that's not very interesting without a way to make leadership better. If you can convince people you have that way - you'll get a lot of interest.
I don’t agree, mind you, but someone reading your comment with this mindset will probably be reinforced rather than swayed.