No, no they didn't look better in the 60s, 70s and 80s. I lived through all those decades, and I think people are healthier and on average 'better' looking that they were forty, fifty or sixty years ago.
I certainly looked bad in all those decade. I had chipped teeth, basin-cut hair and round NHS glasses in the sixties; I rocked those platform soles , which looked ridiculous on my skinny legs, in the seventies, and I went Punk as the decade moved on. In the eighties, I was in my twenties and tried to power dress to impress. It was all hairspray and pads.
Yet, it was not just fashion that made us look worse that today's population. In the sixties, there might not have been more child poverty than today, but it was more severe. More adults wore dentures, indeed there were reports of people having all their teeth removed and NHS dentures fitted as a wedding gift. We ate an awful lot of sweets. Petrol was leaded and there was still pollution from industries. The environment was not a healthy one.
In the seventies, as others have said, we smoked. Schoolchildren could buy cigarettes with their dinner money. In fact, I can remember going to the shop that sold single cigarettes for (I think it was 5 p). Sugar free drinks were not a thing, so our teeth and skin was not all that good. As for the long hair and droopy moustaches!
In the eighties, there were some crazy diets and fitness had just become fashionable.
No, we may look at old photos and videos and think how lovely people looked. I look at an old photograph of my mother and father in the mid-fifties. My mother looked so elegant in her fitted coat and little beret, and yes, she got a lot of exercise dancing and playing sports (which were the ways people met others in those days). However, life expectancy was lower and people died of diseases that are easily cured or prevented now.
Olivia Newton John looked fantastic in 'Grease'. I remember watching the film as a teenager, smoking Players cigarettes at the back of the cinema with one of those droopy haired boys. We didn't look so good.