The problem is that you literally need a budget of about $300 million per year just to maintain a web browser engine, because it is one of the most complex pieces of code ever created, and it has to support a mountain of standards that keeps growing and be backward compatible with the last 25 years of standards, and it has to be constantly improving its performance to deal with the increasing processing demands of JavaScript and CSS, and plug all the security holes. Maintaining 25 million lines of code is incredibly expensive and rewriting its pieces in Rust to have better performance with parallel processing and fewer security holes requires paying for high quality programmers.
At this point, there are only 3 entities even attempting to maintain a performant web engine, which are Google, Apple, and Mozilla. If we all abandon Firefox, then we are left with just Google and Apple in the W3C committees that can implement the web standards and we won’t have a single voice of sanity in the room with any power to push for users’ rights and privacy. Mozilla is far from perfect, but using the alternative browsers means giving more power to Google to control the web standards, because almost all the web browsers that claim to respect user rights are based on Google’s code, so you are giving Google more market share.
Mozilla does a lot of things that I dislike, and it is far too dependent upon Google for its funding, which makes it hard to oppose Google. However, Apple isn’t very active in the W3C committees, and they are increasingly dominated by Google (and Microsoft to a lesser extent). This is why I keep using Firefox, and why I encourage people to buy their services such as VPN, because Mozilla is far better than the alternative.