So I tested both FireFox and Edge real quick and it's true.
Although, I enabled every security and privacy setting on both (just about the same set of extentions also). But even then, even with a lower score, Edge still feels much smoother to use. Also, every time test refreshed, FF flashed white for a split second as opposed to Edge's black. Since I use dark mode and Dark Reader, it's extremely annoying on FF's part.
Chromium-based browsers still trounces Firefox on the Jetstream benchmark. I mean, I realize the Speedometer benchmark is supposed to test real-world scenarios, while Jetstream is more synthetic, but whatever work mozilla did to improve performance I'd expect to scale in other benchmarks too, so I'd expect Firefox to at least be bit closer to Chromium, even if losing a little.
Mozzila re-writing parts of the browser in the rust programming language has made a decent improvement to the performance. For those who aren't to into programming rust is has a strict compiler, meaning better code quality (Less Bugs) and offers more optimization methods then other programming languages.