I'm a falconer. Basically no one uses owls for falconry because they have poor generalization intelligence. They have a really hard time transferring knowledge from one situation to another. So you get them flying to you inside and they are nailing it, then you move outside and it has no idea what to do. Every new situation needs to be trained. They are fine for shows and stuff when they are doing the same thing over and over again but constantly putting them in new situations like hunting would do is a recipe for disaster. A "lot"(maybe a dozen a year in US lol) of falconers try to use owls but very few are successful with them.