My spouse and I would sit through a defensive driving class every three years to keep the discount. They usually cost about $30 per person. They would be either all day on a Saturday or split in half over two days during the week.
Since we've taken so many in-person classes, the AARP online course was an excellent change in pace. Yes, we each had to pay for the course, get our own signons, and take the tests. It's the same way as in an in-person class. The nice thing about the online course is we could take it at our own pace in the comfort of our house.
I can see why you're frustrated if you've never taken an in-person defensive driving class before. They can be so boring. At least the AARP class was designed for the "older" driver's perspective and was surprisingly interesting. When the current three-year period ends, we'll definitely take the AARP course again.
I just checked. The Texas requirement for DD is a six-hour course. If Barber took the AARP course, I don't know how it was done in three hours since the course is a paced course.