You're saying this while the top thread on HN at the same time is how Firefox is artificially slowed down on Youtube lol. That is why they lost market share. Not because they lack the incentive to shove ads in your face, but because companies that run the internet also run Firefox's competition.
Firefox is objectivele fine. Linux is fine, openAI as a research institute would be fine. They aren't stagnant, they're being gutted or undermined by competitors that will not see them succeed.