JS-heavy sites are night-and-day faster on iOS, thanks primarily to faster CPUs (which is mostly due to better L2/L3 caches). The iPhone X has 8MB of L2 cache; your sub $200 phone likely has no L2 at all. Even high end Android phones have, at most, 1MB of L2 cache. This shows up pretty clearly in Speedometer scores.

https://browser.geekbench.com/ios-benchmarks https://browser.geekbench.com/android-benchmarks