That's what sizing guides are theoretically for, if you add more sizing systems it gets even more confusing. I don't think the issue is as bad as the post portrays it though. Its true that sizes can be all over the place but like I am size small woman's and if I buy small most of the time it will fit or at least somewhat fit. I am not a standard model size either as I need things that are for more hourglass figure rather than straight but that just requires being selective about which styles to buy. A medium also usually fits if I need something looser. I double check the reviews if its online or try it on in person and as long as its not something that requires precise measurements its usually fine. For things like jeans I shop in person and try things on from a few sizes or just know approximate size I am or rely on reviews. Many items these days are stretchy and even when they don't fit perfectly they are wearable or you can return them, its not that complicated. I do only shop a few brands or from in person stores or I can often approximate sizing from how big something looks or by looking at review photos.

The pockets thing is similar, not having pockets is annoying but its not that big of a deal. I rather buy something cute without pockets than search for something with some. If it has them great, if it doesnt oh well I will just use my purse. Barely anything fits in pockets anyways and I have a feeling other women feel similarly which is why many of us buy things whether or not they have pockets.