Yondr pouches don't actually block RF, they just physically prevent you from using the phone because it's in a sack held closed with a magnetic lock.
1) Still continue to have a life
2) Not have my phone completely disabled just because I went to see a comedy gig.
Having to leave the comedy gig when my phone starts vibrating in the bag is a good compromise, as is wearing a smart watch that can notify me exactly what the call or message is about before I do.
The selling point is to reduce visual / audible recordings of the performance, allowing artists to say or do things that may be problematic when taken out of context.