If you desire a desktop-class browser for your iPad, I'd suggest looking at iCab Mobile.
It's the closest thing to a desktop browser I've used (since Mercury, before it was sold and ruined), with myriad customization, functional, and import/export options, including direct support for the major ad-blocking lists (it does not rely on iOS' system content blocker). It's more like Firefox desktop than Mozilla's own iOS browser is, and the developer is responsive to users.
A browser is far more than its rendering engine. To suggest otherwise is silly, and akin to telling the developers of Edge, Vivaldi, Brave, etc. that they have no reason to exist, just because they employ Blink like Chrome. That also applies to iOS.