IRC didn't require e-mail AND phone number to use it
Getting one’s account stolen on IRC because of NickServ was common occurrence with new users.
I couldn't care less about my ephemeral IRC account getting used (not sure why you call it stolen, if it's just there for anyone to take) by someone else, it's for sure much less important to me than sharing my email AND phone with some corporation, especially considering email would be more than enough to verify the user.