Explain to me why I can't go topless please.

Because of the Male Gaze.

I don't go topless as I'm embarrassed by my very tiny boobs. I hate seeing other women do it as I'm jealous 🤣. But I think we've been historically conditioned to think women who do go topless are doing it just so people look at them, to get attention. It's hard for me to say as I'd never do it.

DW never had qualms about breastfeeding either,though it’s over 20 years ago now she was once asked not to by a staff member,in the cafe of a large department store that still exists, when she asked where they expected her to go, she was told to use the toilets, she asked to speak to the store manager and invited him to eat his lunch in the toilet with her while she was breastfeeding, suffice to say she was allowed to stop in the cafe, sadly though I still see women today being made at the least to feel uncomfortable doing the same, attitudes are difficult to alter

Nor me!

Well you can, you won’t be arrested. It’s only an offence to intentionally expose genitals. Although it’s less acceptable in society, women have equal rights to men when it comes to public nudity.

Well I wouldn't expect another woman to cover after a double mastectomy no.

I think we learn to categorise this sort of situation based on how we were taught, both explicitly told, or read for example by our parent/ guardians etc or rules in a specific location. Also by observation of wider society at that time.

So as an example I live in a country where topless sunbathing at the beach is not unheard of but you wouldn't see full nudity.
Girls up to 8/9 generally don't wear bikini tops so that's the norm here but I know it's different elsewhere.
Men wouldn't expose their chests anywhere that wasn't a swimming location, despite the heat, so it would be unusual for me to see either sex bare chested at the park.

To be honest I think that some people may feel uneasy, but not because of anything sexually related but because they attempt to shield themselves against the difficulties that life can bring by pretending they don't exist. In the same sort of way some noticeably find it difficult to be around people with disabilities or very old and frail people or hear about tragedy of one sort or another.
I think that they find the thought of it distressing and disturbing to be reminded of "real life " rather than a distorted " perfect life narrative" they desire.

So in answer to your question, although I'd clearly notice, I wouldn't pay much attention as long as it were in a location where it could be expected, based on where you live.

It's interesting that you say you are not bothered by exposing any of your scars. Your body is readily identifiable as female, even without breasts. Perhaps some of the reasons others are uncomfortable at the idea of you exposing your breastless chest is that the scars will upset them, and that your female-coded body will freak them out by its scarred difference to the norm.

And we have been taught to hide our scars. So, despite your openness about your scars, you may have internalised some of that.

Please excuse me if I've used overly blunt or inappropriate language. I'm lucky that it's not a situation I have had to navigate. My only comparable experience is coming to terms with a medical condition and the permanent changes it caused on my face.

My daughter asked the same question when about 6 or 7. "Why can't I wear trunks, why do I have to wear a swimming costume"? I really struggled to answer her. In the end I think I gave an overly long answer about customs and traditions sometimes applying to large groups of people (i.e. female adults and children) without really being thought through. She lost interest half way through.

And yet all these young females getting mastectomies because they say they are men, are applauded for being photographed with their scars and are not censored online.

Was the first thing E. Paige did. Topless 'man' photoshoot.

Interesting question. Possibly due to the sexulisation of breasts, and the simultaneous control of women's sexuality with concepts of modesty and shame, compounded by unwanted male gaze. I think that this is so ingrained that female chest covering is expected with or without actual breasts, maybe the idea that this is the area that breasts are normally expected to be is enough to make people uncomfortable with it being naked.

Completely agree , it’s decades of conditioning, being told it’s unacceptable, let’s be honest, it’s still frowned upon by many if women dare to breastfeed in public

It's because society tells us that this area of a woman's body will inflame the lusts of men.

Yes, hyperbolic but that's what it comes down to.

It's why you get threads on here expressing disquiet at seeing prepubescent girls without tops on, and why actually having breast tissue to display is neither here nor there.

Even if you've got a completely flat chest it's still a marker for SEX so you must cover it up or woe betide.

C.f Victorians and ankles.

Interesting question and yes, I think it is decades of conditioning.

Rationally I can’t think of a good reason to cover up (both in your case and generally) but societal expectation is for modesty from women when it comes to their chests/breasts.