I can name a couple other reasons why FF is better:

1. I get way more lower-level control via about:config over internals than chrome's about:flags (i.e., adjust caches, buffers, networking strategies, GC thresholds, etc.)
2. I can fully disable newer ad delivery mechanisms like Service Workers and WASM at a core level (NOTE: while these were initially touted as ways to speed up the internet, they unfortunately are used mostly as ad-blocking and tracking circumvention measures now; its also easy enough to re-enable them temporarily if a site uses one for legitimate reasons).
3. Actual, no-kidding, site cannot override, auto-play blocking (via some about:config tweaks).

With the newer FF versions they landed some very nice speedups, but with some of the tweaks i've made, basically FF be zoom'n now 😅