And here I was thinking this was proved beyond any reasonable doubt when 4chan users spoofed the Time Magazine person of the year poll of 2009 to spell out "MARBLECAKE, ALSO THE GAME" by the initials of the top winners:
You need to though. If you only do phone call polls you're only going to poll people with (landline?) phones who answer (random?) calls and have the time/enthusiasm to respond when you call. That heavily skews demographics.
A lot of people will only do online polling, and it's by far the easiest way to cover a lot of demographics (need to supplement with other methods as well if you don't want a poll of "internet users" - but that is a far larger and varied group than most other methods would produce)
https://techcrunch.com/2009/04/27/time-magazine-throws-up-it...
Or when Kim Jong Un won in 2012:
https://observer.com/2012/12/4chan-successfully-votes-kim-jo...
A lot of people will only do online polling, and it's by far the easiest way to cover a lot of demographics (need to supplement with other methods as well if you don't want a poll of "internet users" - but that is a far larger and varied group than most other methods would produce)