Here is my experience with H.S.A. certified buddies, your experience may vary.
I have dove as a dive buddy with paraplegics, and quadriplegic. Some local, some visiting from other countries. None that I knew before. H.S.A. maintains a database with Dive Buddies and DMs and Instructors listed.
That said, most dive buddies get trained so they can assist someone they know. A friend of mine just got hired as an instructor in St. Croix, US Virgin Islands. A key part in his hiring was that he was an HSA Instructor. Dive buddy is at the non-professional level so it would not play a role in getting employment. At the professional level of DM or Instructor, being qualified to instruct adaptive diving or to DM or lead an adaptive dive would I believe give you an added dimension and that would of course give you and edge in employment. When talking to a prospective able bodied student it definitely gives me an edge when I point out that I have taught quadriplegics. The thought process being on two fronts, 1. If a quadriplegic can dive, I can dive and 2. If he can teach them....
But most of all being an HSA DM/Instructor or Dive Buddy offers the following benefits:
1. will cause you to step up your game and be a better diver
2. will give you an opportunity if you ever dive with an adaptive diver to get paid so much more than money can eager pay. I can not express how appreciative my dive buddies are that I have taken the time to learn something so they can dive and well it just is a lot of fun.
Last of all, I will point out that HSA certifies at 3 levels and only 1 requires a specially trained dive buddy, but the other 2 levels can benefit from it.
I started a non-profit to train disabled veterans to scuba dive. It is both fun and thearpy for them. You could get involved in an organization like that near you.