How is this still not a thing?

When it comes to shopping for clothing as a woman there's nothing more frustrating than trying to figure out what size you are in different stores. Given that we're now all shopping online for clothing this has become even more noticeable and I'm sure I'm not the only one who has had to return things that were marked online as being their size but was actually way off the mark. Just looking through my own wardrobe I'm shocked at how varied the sizes are from one brand to another. In one store I'm a size ten while in another I'm a size extra large and the clothing is exactly the same size. Pictured are three pairs of trousers of mine that I would wear regularly. They are from three different retailers and are three different sizes, ten, twelve and fourteen. If they were measured in inches like men's clothing they would all work out roughly the same size, except maybe the size fourteen, which while being marked as the largest in the bunch is actually the most snug fit out of all three pairs. But there in lies the problem. How are we supposed to know the right size when companies just seem to slap any and every size onto an item of clothing without taking any measurements into account? Another problem with women's clothing is the whole small, medium or large debate. As I mentioned above I own clothing that is extra large but these items are not over sized fits, they're simply the size that fit me out of that particular range. That means that this brands largest size is a 12-14, which I would considered to be a solid medium rather than extra large. I feel sometimes that marking a medium as extra large can sometimes be a cop out for brands to only include smaller sizes in their range but market them as being inclusive. It's easy to say your brand is inclusive because it caters to sizes small to extra large but is it really if people above a size 14 can shop from it? In an era where we talk about progression and diversity isn't it time that we really saw those things implemented fully in women's fashion? Not only do we need to see fashion in more diverse sizes but we also need to see standardised sizing in women's clothing like there is for men. No more guess work, no more being a small one place and a large in another, just a straight forward guide to what sizes are what. Oh and while we're changing things can we have real pockets too? Thanks.