I think perhaps you are overestimating the computing needs of the majority of the population. Get one of the iPad cases with a keyboard and an iPad is in many ways a better laptop.
I'm not sure - I just looked casually at some options and it appears one can find an iPad between $700-$900 for a pretty solid model, which includes the $250 folio keyboard. The base model MBA starts at $999. So depends on whether you want a traditional laptop or a "computing device."
The problem is that almost everything, including basic web browsing, is straight-up worse on the iPad. Weird incompatibilities, sites that don’t honor desktop mode, tabs unloading from memory, random reloads, etc. all mar the experience.
I'm guessing you are coming at it from the perspective of a laptop user and likely a power user. The majority of the population just needs to scroll social media, message some friends, send an email or two, do a little shopping, maybe write a document or two. For this crowd an iPad is plenty. When I was a software developer - yeah, I had a Mac Pro on my desk and a MBP I carried when I traveled. Now as a real estate agent, an iPad is plenty for when I'm on the go.