Are opticians just glorified salesman's now?

A few years ago, at age 38 and with a lifetime of very good vision, I noticed that everything had started getting really blurry - going from normal to quite concerning over the space of a month. I went to a high street optician to get my eyes checked. The optician did all the tests - the usual getting up close to drop the lenses in etc, and found that my eyesight had deteriorated. I said that it was very odd because it had happened over the space of a month, and he told me that I was "just getting old" and that it had "probably been getting worse for a while and I just hadn't noticed", and sent me back out to buy some glasses from the front of shop. "Isn't that much better now?!" they said triumphantly when they gave me some to try on and told me to look across the street. Something still didn't seem right though, so I didn't buy the glasses and went to my GP for a second opinion. The GP took a urine sample and sent me away, telling me to avoid sugary things until they had results. I remember I nearly passed out at work that afternoon. The next day, I got an urgent phone call telling me to return to see a different GP. Within a couple of minutes of being in the room I was told "There's no doubt about it, you have Type 1 diabetes. We're going to do what we can to try and keep you out of hospital tonight". When the GP was making calls to the hospital outpatients diabetic department she said, "its definitely Type 1, going into DKA \[diabetic ketoacidosis\], I can smell it on his breath". I had been feeling tired and ill and urinating a lot during that month where my eyes were going funny, but it was the change in my vision that sent me to see anybody about it. If I'd just accepted the optician telling me that "you're just getting old" and bought his glasses then I would have ended up in hospital within days and potentially in coma. Something completely missed by the optician who wanted to sell me glasses who dismissed it and made me feel like I was being silly. That was the first time I'd been to an opticians for 15 years (always had very good vision until then) and that experience absolutely cemented in my mind that they are just glasses salesmen who cared more about selling glasses than about your health and that such (semi-)privatised healthcare does not have the patients best interests at heart! A month after starting on insulin, my eyesight had returned back to normal, I arranged for a re-test at the same opticians as my eyes had improved. They scoffed and told me that the prescription can't have changed in such a short space of time and that I'd be charged for the re-test unless they found a change. My vision had indeed returned to 20:20. They seemed disappointed.