I'm glad you like Firefox, I spent a lot of years on it, and on Mozilla, Gecko, SpiderMonkey, and the XUL platform before it. But Mozilla is currently beholden to Google and this has left them with year over year market share losses against Chrome. I don't see how they've "undermined" Google. If they switch to Bing as scooped by TechCrunch, they may start.
Yes, I'm quite familiar with your record - you sell it endlessly. Your getting in early at Mozilla doesn't make up for the damage you've done to the web with Brave.
I'll gladly explain for the other people who might be scrolling by, since time immemorial has proven that user feedback falls on deaf ears at BraveCorp.
The internet is not made "good" by by browser manufacturers. This is something we fought about when Chrome assumed dominance, and it holds true today. The thing that makes the internet good is content: a perfect browser does literally nothing except format content properly into an open window. That's why power-users will still reach for Firefox, Chrome, or god forbid Safari before they consider trying "the cryptocurrency browser by a guy nobody trusts". Hell, I'd probably install the stupid Opera Gaming Browser before I'd be caught using Brave. That only leaves you the market of people who would like to earn pennies on the dollar browsing the web, but also pay for their DSL access every month. In all fairness, it's a market you've capitalized on very well, which is why it so closely resembles abuse. If it looks like a duck, walks like a duck and talks like a duck... I won't believe you when you're telling me it's actually a lion.
You are quite mistaken on "format content properly", as Firefox based on Gecko does not agree in detail (esp. on mobile) with Chrome, so people tend to go to Chrome over time. Worse, as Firefox loses share on this basis (among others), sites whose webdevs test in Chrome and Safari only (Edge is Chromium-based) tend to break Firefox. This spirals down. But keep pretending browsers are passive, blind formatting engines!
In fact Google did Chrome because it learned from Firefox that browsers are high-value user agents, and if they camouflage as passive/blind agents, then the big tech network superpower can have its way with the user, both through top sites such as Google search tied into default omnibus search engine setting, and over time via Google's browser tying (an antitrust term) other Google products, Google's accounts and analytics systems, and even full ad-exchange user-tracking, into its browser.
As for user feedback falling on deaf ears, you are simply making stuff up. Chrome ignores user complaints, Firefox too (roasted endlessly over killing XUL add-ons, Proton UX, etc.). Brave is all over Twitter and Reddit and we do live customer support there. I spend a good chunk of every day on it.
As Chesterton put it, one can always be blind to a thing so long as it is big enough. That seems to be the case with you and your "format content properly" statement here. If you are a Chrome user, I hope you disable account-based tracking in your Google account(s). If you use Firefox, ditto, and beware tracking pixels they whitelist on Google's SERP.