Okay, but the machines don’t create and maintain themselves! The technological industry has closed many jobs but opened up others.
In general, I purchase flight tickets online. Last year, when I took a family trip to Israel, we used a travel agent to plan out the trip since we were making our own schedule and not going with a group- we needed information on what places were family-friendly, etc. So for the express purpose of buying tickets, I don’t think there’s any advantage to using a travel agent, but in terms of trip planning, they know a lot of useful information that can otherwise be difficult or time-consuming to find.