I think people's responses change dependant on age, size and upbringing.
I can't comment for most people but those that I know this is a reasonably common topic of conversation. Truthfully over the age of 40 most of us wear what the hell we like. Accounting for work rules and appropriateness (to an extent I have noticed that some of the mums at school have made up stupid arbitrary rules about what's appropriate at the school gate. Entertainingly I fit their requirements and it's got nothing to do with them.....I just wear what works for me but I think some of the less than accepted mum's look bloody marvellous. And yes I've said so).
When I say appropriate it's for the weather or you know not wearing an actual bikini to the school run.
That said you always find the odd one in real life who hoiks the bosom and lays gems on everyone about dressing for size or what's "in" or appropriate. They have without fail turned out to have massive body issues and hangups and feel insistent to foist them on everyone else (as per the school mums above).
Truthfully after a certain age I find most people roll their eyes at people like that and snigger a bit. In your teens and twenties we all worried and now if I'm honest it seems a bit laughable to get hung up on not wearing certain things because of size or age.
The only people who witter this in real life are the ones that most people think are ridiculous or feel a bit sorry for them because they are so insecure.
Online of course more people witter away and think it's terribly insightful to comment on other people's clothing choices.
I rather like in the group of people I engage in there are all different shapes and sizes , some casual, some gym wear, some highly polished and some dressed to the nines. The only people that get laughed at are the ones who create these stupid rules. We generally assume they peaked in secondary school and stayed there.