Sure you can - you type it in just like text, works great - I'm sure other terrorist organisations like ISIS do the same thing

So how much traffic would Google.com lose if they switched from DNS to just an IP? None?

If they choose to base themselves on extremist idealogy, it is their problem to figure out how to sustain themselves let alone craft its own monetization plan!

One perspective is that Google runs their own DNS that many people and services use as a convenience.

Also, as I get chastised for using Bing (because they pay me) and much of their traffic comes from browser defaults, it's arguable that if they stopped hosting on google.com it may not be that negative of an impact.

To the same degree, note that Amazon CHOOSES not to list their more specific apps in the google store and force customers to download THEIR store and change their phone permissions.

Sounds specifically like a problem of terrorists organizations and their marketing departments.