1. Innovate
2. Dominate
3. Enshitify to cash in.
You can't skip step #2.
Right now, Firefox's market share is a rounding error compared to Chrome. Users are starting to switch away from Chrome because it's currently in step 3 (in spades). That trend will not continue if Firefox beats Chrome to the bottom of the pig-pen. Firefox's current focus on AI is concerning enough, but mirroring Chrome's shift to Manifest v3 (i.e. What killed full-blooded ad blocking in Chrome) would be outright suicide.
Mozilla needs to listen to their users. Most don't particularly want "let me run that through an AI for you" popups everywhere. Practically nobody running Firefox wants to be cut off from effective ad blocking.
Monetization is hard, for Mozilla in particular. It was always weird that most of their funding came from Google. Now that Google is yanking it, Mozilla needs to find alternative sources of filthy lucre. However, if they destroy their product's only competitive advantages, there will be nothing left to monetize. If Firefox remains a browser that can provide decent privacy and ad-blocking then Mozilla has a chance to find alternative revenue streams. If, instead, Mozilla throws those advantages away to make a quick buck, that's the last buck they'll ever make.