It's very subjective, but I won't try switching again before certain things I value in Chrome are available or work similar well on Firefox. You can switch based on ideology alone but I want convenience more than that.
Other than this ad stuff (which I agree is tremendously hostile) Chrome has acually been getting better. The dev tools, performance, UI, and memory usage have improved considerably this year.
I assume you have good intentions and want to advocate for Firefox and have it have wider adoption. I want the same thing, but it's imo not enough that Chrome gets shittier (it doesn't in my opinion btw in terms of UX), Firefox needs to become better to win.