https://pretix.eu is having some success in the EU market. But other sibling posts correctly point out this is… let's just say "overall shit situation".
We also have Eventim and many other local ticket shops. I usually get my tickets right at the venue's online shop, or maybe from the artist. They use all kinds of systems.
They captured like 90% of the German ticket market by closely watching Ticketmaster and basically repeating their playbook. Eventim also owns some venues, has exclusive contracts with many of them it doesn't outright own, hosts an official fan resale site, offers promotional services and generally integrates a lot of the business around large events vertically.
What's actually interesting is that it seems to be possible to compete with Ticketmaster only by copying their playbook on a large-enough scale, and Germany appears to be large enough. The Netherlands right next to Germany don't seem to have been large enough, as Ticketmaster basically controls them.