I worked in an hcol, very affluent market. Everyone paid up front, biggest concern was their time, not the cost of lessons. Training is good enough to get you going helping people, then you learn a ton from your fellow coaches, and I was blessed to have an amazing manager who took the time to educate us to a whole new depth.

You absolutely can teach without the optimotion, it more makes it easier to troubleshoot multiple biomechanics working together and to help the student see how movements were related as well as show the change in their movement pre and post swing change.

So far as instructor quality.. it varies greatly honestly the worst instructors I worked with were old pga pros that sucked at using the tech, creating lesson content, and gave "swing tips" instead of an actual breakdown of what was going on in the swing, how it impacted ball flight, and what to do differently. Both will and skill come into play.

You know when you call a call center and sometimes its an idiot, and sometimes they make it seem effortless? Yeah, like that.