I think this reason is stupid. Why can’t there be a duopoly in the browser market like in the phone market? Even if there is no firefox, there will still be safari on its own engine
I think the phone market should also be broken up.
The reason a doupoly is bad in any market is that it’s essentially next to no choice for the consumer, and the businesses can force changes to the market that are anti-consumer with little reprocussion. In any given market the minimum number of legitimate competitors necessary for meaningful competition will be different, but even three is too few in the web browser game, especially when the market shares look like this.