I think it's a good argument that you shouldn't need to do this but like everyone my age got their first car loan and apartment with their parents cosigning. It's super relevant to the the US economy today.

It's possible to get credit without someone else but you'll get an absolutely terrible interest rate -- if you have someone in your life with good credit that trusts you (like family) you're leaving money on the table by not 'borrowing' their good credit.