The beachbody workouts are actually pretty good, just don't buy their overpriced shakes and other stuff. My GF and I share a monthly sub to the online workouts. It's considerably cheaper than a gym membership and more effective, at least for us. No trekking to the gym, fighting for weights, people who don't wipe down equipment, etc...but yes, I have known a couple "coaches". Not sure what exactly they do.
They "give support", make recommendations, and run Facebook support groups.
So, for example, a new program comes out and they get people to sign up and pay for it (new programs don't come out on BOD for several months, so you have to pay for early access). Then, they pick a "start date" and they all workout "together" and high five each other, etc. Some coaches are actually fitness trainers or nutritionists, so they can also make dietary recommendations, etc.
For certain people, it can be helpful. Much like WW, some success comes in with a feeling of belonging.
One of the people I know locally who is a BB coach actually owns a fitness business and (when gyms aren't closed), runs twice daily workouts, meaning he has a large screen TV and he and the folks who show up work out together. (Usually only 1-4 people, tbh.)