The last question that was asked about this was in 2013. While looking at the question the site I found that it was pretty outdated. Yahoo has recently made some changes where I cannot go to Yahoo without a phone number. I would like to know is there any way that I can pass this or join Yahoo without one? I want to make a new more professional account.
Haven personally tried it myself, but you could actually try it. Use a "fake" number to "trick" Yahoo.
There are services that provides numbers that can receive SMS online: link