Ad blockers pretty much all rely on community-maintained block-lists, there are always going to be mistakes in those that break some sites, or some sites might not act well when unable to send ad/tracking events. I recently had an issue booking a train, which was because of this, turned off the ad blocker and it worked fine, not something that's as easy to do with network level blocking, especially if it was set up by someone else and you're not a technical person. Not booking the train because their site is bad is not a realistic option.