That's a valid concern, and with a classical centralized DB the Edge solution will not be faster in many cases, especially considering how many DB requests some

That's a valid concern, and with a classical centralized DB the Edge solution will not be faster in many cases, especially considering how many DB requests some ORMs like Drupal or Wordpress need for each page load... Some other providers have tried to solve the problem with replicated databases that are used for local reads. I can't go into details yet, but Wasmer will offer a solution for this problem quite soon as well, which hopefully will be much more seamless than existing strategies. (note: I work at Wasmer)