Just showing the app filling the viewport isn’t fair because iOS and android handle splash screens differently. All of my side-by-side comparisons are waiting until the initial load completes.
I am running grapheneOS, so slightly different, and you might say that’s unfair. I’d expect a distro without the bloat to perform better, but it does have extra hardening to try to get closer to an iOS level of security. I do consider that a fair comparison, since that is the bare minimum you need to trust the device. Looking at the network traffic of an android device really gives one goosebumps, even in the best of circumstances.