Is it unreasonable to ask Vinted or Ebay sellers for clothing measurements?

[NedsAtomicWheelieBin]

If I go to a shop I can try something on to see if it fits. If I buy something from a shop online I can buy a size up or down to find out what fits best and can return what doesn't fit. But if I buy something from Vinted or Ebay I want to know the measurements, underarm to underarm and neck to waist/hem. It's all well and good saying it's a 12 or 14 or 16 or a Medium or Large, but that doesn't really mean anything. So if I am interested in buying something I always message the seller asking for the measurements. So few sellers respond. I know this isn't AIBU but am I? Clothes sizes vary so much and I just want to know if something is likely to fit before I buy, especially when most don't accept returns.

@parkezvouswhy? Surely asking the length of a skirt or inside leg measurement is perfectly reasonable- and if I was selling I’d know that and put the measurements in the listing in the first place!
@AmIReallyTheGrownupwell thats great for you, but not the reality for many. My DD has just come back from thrifting in the US and she has clothes from size 6 to 12. Sizes change over time and between manufacturers- surely you understand that? If you are buying something fitted or trousers in particular and are unable to try on then measurements are essential.

Tops Shirts & Jackets I can wear size 14 16 or 18 so pit to pit size is necessary for me, also trouser inside leg measurement.

I don’t even know what my inside leg measurement is!

Believe me, this world exists. I have clothes in my wardrobe in sizes ranging from. 0 to 12. They all fit.

Same - I have soze 10 to soze 16, XS to L, and all fit. That's one reason we have changing rooms in shops and why measurements are so helpful when buying online. I'm an hourglass, so while a 12 might fit me in one style or from one shop, it will be too narrow on the hips and too wide on the waist in others - so I can't even be guaranteed that a 12 from Next for example will always fit me.

Similar situation here. I have come to the conclusion that hourglass is by far the hardest shape to dress. There are too many measurements which make or break whether something fits. Even when I was pretty thin it was difficult.

I’ve literally never seen anybody list measurements on Vinted. The only time I’ve measured something for somebody was a reformation dress I sold for £100.

Surely is the risk of Vinted, somethings don’t quite fit as you like so you sell them on again.