“You can buy cheap Android but if you go much below $399 you’ll be replacing it a lot more often.”

The Moto G is a cheap phone below $399. It was horribly slow. I was referring to that sentence.

As far as high end phones Benchmarks comparing GPU and web performance for high end Android phones compared to iPhones are readily available.

The iPhone 8 is now two and a half years old and is still faster than any Android phone.

Also, compare the performance of the $329 iPad 6th generation to most Android devices.

https://browser.geekbench.com/mobile-benchmarks