I had extreme response time issue on my old phone. I recorded my screen, and I measured a reliable 3-5 60Hz frames between the touch indicator and the page scrolling. Chrome reliably had just 1.

Things got a bit better over time, but unfortunately the thing that eventually fixed it was when I got a new phone. Now I get around 2-3 90Hz frames, which is still worse than chrome, but far less noticeable. I have not measured "New Firefox"/Fenix/Preview yet, but it does feel like it's a bit closer to chrome.