I’ve used C1 and its only advantage is superior tethering support and live tweaks while tethering. It’s also a better organized app in my opinion; Lightroom basically grafted its Camera Raw app into Lightroom with some tweaks, and it’s a little clunky (certainly much clunkier today than Apple’s Aperture was a decade ago!).
But the Lightroom/Photoshop combo is much more powerful plus C1 doesn’t accept plugins (eg the Nik Collection, Imagenomic Portraiture, Topaz plugin, etc - I rely constantly on Nik’s Silver Efex Pro for unparalleled b&w adjustments). And C1 doesn’t work as easily with iOS - with the Adobe subscription you can log in and automatically unlock all editing features in Lightroom Mobile (which has separate apps for iPhone/AppleTV and iPad).
The standard Lightroom Classic + Photoshop subscription (with 20Gb online storage and photo gallery) is $120/yr, or you can get it with Lightroom only but 1Tb storage for the same price (or Lightroom/Photoshop + 1Tb storage for double the price).
Also, the price of C1 - purchased/upgraded or subscription - offers no savings over Adobe but still lacks full access to Photoshop and online storage/sharing/gallery.
And if you stop cancel the Adobe subscription you can still view and export all your images, but they disable the Develop module.