I think it depends on your priorities and needs.

I just booked a round trip for myself, plus two more flights for quicker hops while I'm away, and I didn't spend much time on it at all. I just looked at Google flights, picked the flights I wanted, and then ended up buying them through Chase with points. Chase's travel website is among the worst I've ever used, but it wasn't hard. Then I went to the airline's website and changed my seats (Chase doesn't know I have status and couldn't directly book the seats I wanted) and did an upgrade for one of the legs using miles I had at the airline. Half hour of work, maybe?

The price-setting algorithms are garbage, but an LLM isn't going to fix that.

Agree with the other sibling posters that if this annoys you so much, you should just call up a human travel agent. I haven't used one in many years, but when I did (mostly for business travel), it was always pleasant, and the agent knew my preferences and took care of things if there were any snags or changes needed. At the time, they usually got me flights cheaper than if I were to book them myself, even with their fee on top.

But I do wonder what the profession is like now. I can imagine some sort of website where you often don't even deal with the same person, who won't get to know your preferences and will be sort of like a customer service agent, just trying to close as many cases as fast as they can. But hopefully there are still smaller shops around, where you can talk to the same person (either phone or email) every time. Dunno.