Do Oral Health Therapists Perform Routine Checks Now?

I went to the dentist the other day for a routine check up and clean

I was reviewed by a oral health therapist who I thought would do some of the initial check and would be reviewed by a dentist at some point, but they did the entire routine check by themselves

Turns out I had a deep groove which required a filling to prevent decay and the oral health therapist had booked an appointment in a couple days and was going to do the filling themselves as well

I told the receptionist that I was under the impression that I would be seeing my dentist like I had been booked in to see. I saw the oral health therapist roll their eyes when they heard I wanted to be reviewed by a dentist. Istill had to pay the same amount as if I had seen a dentist.

I called back later to ask for a dentist to do the filling.

Just wondering whether this is usual? Was it rude of me to demand a dentist? Are routine checks and cleans done by oral health therapists these days?

I don't know the scope of an oral health therapist, but for example if I had a medical problem I would want to see a GP vs someone like a nurse/paramedic who hasn't received the same type of training.