Are they? I was under the impression that they mostly work on referral fees/commission. They get paid by the hotels, airlines, cruise companies, etc instead of booking.com or wherever you would look things up yourself

With that, I thought people stopped using them because most find some value in planning their vacations themselves, and the barrier to doing so got easy enough for them to do it. There's a huge subjective component to a lot of choices involved in a holiday. A travel agent seems ideal for someone willing to give up control of those specifics, that just wants to be able to send an email that reads something like "15-28th August. Portugal. I'm thinking something involving forests" and be done with planning.