Yes and it depends to both questions.

I participate in projects being developed on Github that have 5k+ open pull requests and the same amount of issues. At that volume of communication, the Github workflow of "clicking through stuff" is way inferior to an efficient email workflow. Essentially, your workflow turns into email anyways because its the only sane way to consume based on push, and yes, I know, you can reply to Github using email, but its not nearly as good as something made for email.

So, in my opinion, email is simpler to use that pull request. It is not easiser because it is not close to what people are used to.