Link it though your google account why not?
Ok you have to give your phone number for a google account, but so what 99.9% of people will have a google account anyway and if you don't there really is no point been part of the 0.1% still living in the dark ages. So link YT to google and problem solved, why have another unnecessary account with YT, seems so pointless.
Alternative idea go by a cheap second phone on Pay as you Go for around £12.99 most basic thing you will ever see, you will never need to top it up with credit or use it, and just use it for the single purpose of phone verification checks on the web for YT or any other service or site that wants your number via verification, just keep it locked away somewhere uncharged and only get it out again for those rare moments when you want give a fake verification number to a website.