iPad pro vs desktop setup

Hi.

Today i tried my 200ohm Lcd4 headphones with my ipad pro 3,5mm running roon app, for the first time A-B with the ipad pro and desktop setup. And i was shocked that there was such a small difference from my desktop setup wich is imac-roon, usb - moon 430had amp and qutest dac.

Then i found This article

https://www.kenrockwell.com/apple/ipad-pro-audio-quality.htm

I just cant understand that there isnt a bigger difference between my desktopsetup and my ipad pro. Started thinking something is wrong with my desktop setup, maybe it would be better if i use a streamer with roon instead of the imac with usb?

Im shocked over how good the ipad performs.

What resolutions will it play?

Only tried it with roon/tidal hifi. Core is in imac.