Once you have reached a D cup, non-wired bras don't really do the job.
In what way?
I have always hated wired bras. Tried for uears and years, different sizes, brands, fitters, interventions. Every one was as uncomfortable as the last. I did find one from Cacherel years and years ago which was tolerable, but they no longer make bras.
So I’ve worn sports bras for every day since my teens. I’ve always been a 34DD or larger, they’re supportive, i can run for a bus, and comfy.
So why must a wear a wired bra? If’s aesthetics I don’t give a shit. With clothes on how would you tell? My boobs stay in one place and sit in the right place on my chest. I don’t wear thin straps or clothes that show my bra.
Although even in my teen years i used to question why i was forcing myself into wired bras when i hated them. Answer is social expectation- women should wear frilly “attractive” underwear, not comfortable supportive garments. Mostly for the male gaze.
Anyway i shall not be telling any dd of mine to wear underwires. If they want to, fine, but I don’t see anything wrong with an equally supportive non wired bra.