Reddit doesn't require an email. They use dark patterns to make it look like you do, but anywhere it asks for an email in signup can be left blank.
Edit: It works when using the right URL, see https://news.ycombinator.com/item?id=34742134 below.
That experimental part is interesting.
I don't know what they think they are accomplishing since burner e-mails are trivial, but perhaps it gives a semblance of doing something.