I have a question for techno lives

I started listening techno about 10 years ago but I have only been to 3-4 techno lives/fests and I have a question for the veterans of techno. From the events I've been and from what I've seen on the internet many DJs play sets that contain mainly songs from various artists and only few even 0 songs of theirs. Is that a thing in techno? And why should you pay more for some big name DJs if they're not gonna play their songs? I mean, I understand that the more successful the DJ is the better the experience you will get from the mixing skills but I think you get my point.