I have Lightroom mobile on my iPad Pro.
I even have a camera connector so on a recent trip, I used it to load my RAW files from my DSLR.
But I used it only for storage, had no desire whatsoever to edit photos on an iPad. I may try it some day but I'm paying $120 a year for Adobe CC subscription so I'm going to use it on my iMac, with the bigger screen and trackpad for pointer control. I don't do much with masks but I still want that pointer rather than tapping parts of an image to edit it.
The import of a couple of hundred RAW files took a long time and I can't imagine how long it would take to stitch say a dozen images for a panorama. Lightroom will peg my CPU during import, applying presets and stitching. I don't have the fastest CPU or GPU that I could have gotten on the 5K iMac but I loaded up the RAM and I can't imagine how much longer similar operations will take on the iPad, even with the fastest SOCs.
I use Lightroom Mobile mainly to view collections (or subsets) of my photos that I've sync'd from my desktop.
Even if there was processing power parity, I doubt I'd edit thousands of RAW files on an iPad.