iPad as a PC replacement is utterly nonsense.
Not everybody fits in that category but many do. Maybe even most. People who have an old PC lying around to do email and browse the web are far better off getting an iPad to do those things and expand their capabilities with the richness of the app store.
I was skeptical but got an iPad Pro (12.9 inch) as complimentary to my photo editing in Lightroom and the iPad Pro and Lightroom mobile ended up completely replacing the majority of the use of my iMac for work. It's fantastic!