I saw something on this that basically anyone can get a service dog designation. Theres little to no oversight or standards, theres lots of websites that you pay a fee and get a certificate and vest. People are doing it because they dont want their dogs in cargo on a plane, or they want to ignore all the no dog areas around town. Ive seen several at the farmers market and its clearly whats going on.
It used to be 10-15 years ago you would only see this occasionally especially if you saw someone flying who was blind now its not uncommon to see 3 to 5 dogs per flight