I feel the size problem may have more than one reason for failure.
But I would go with the fact that due to most of our trade these days, comes out of third world or developing nations, and possibly they don't adhere to western ways either by choice or ignorance, we find issues such as size and quality are not as important to them and so are not monitored or audited as in the western countries.
I am reminded of a conversation I had whilst being given a sales presentation in China.
During the presentation I was looking at the tools on display on the table in front of me.
At some point I wanted to check the accuracy of a couple of 'set squares'.
I stood them up and put them back to back, only to find that they were not true to 90 degrees.
Whilst the presentation continued I alerted my guy, (who set up the meeting), to this 'quality control' problem in front of me.
Later after we had gone back to the hotel I pointed out that I was vindicated and that the standard of Chinese goods was well below par.
Bare in mind this was some 30 years ago when the Chinese phenomena started.
The point I am making is, when I brought this quality issue up later, my guy's response was a defensive one by saying that China made quality goods, it was just that the western buyers wanted everything cheap.
Now, as much as he wanted me to believe that, and there probably was an element of truth in it, I chose the tools at random when I put the two 'set squares' up against each other.
I did not ask for 'cheap' ones, so it is that their standard was 'cheap' because my choice was random and they presented these items to me as being typical of their production range and skills.
And so it is that we get such inconsistencies from these developing countries.
It may have to do with the western culture being to overly concerned about 'looks', or 'poser'.

A very timely article.
I have been telling firends for some years that 'one size fits all' means this size fits no one".

I am of the generation who sew. My clothes fit me and always have.

I am also aware of the size changes that have taken place over my life time.None of them were announced publicly so that the general population knew what was happening.

First confuse buyers with sizes, then encourage them to think that cheap is the best concept. Now we have an industry which produces ill-fitting rubbish made from cheap synthetics which have no lasting quality and are very quickly going to land fill.

Along with this manufacturing disaster we have a world population of women, especially, who believe they are unacceptable.

'I am of the generation who sew. My clothes fit me and always have.'

congratulations Hilily for your commonsense.
'

Hurrah for real women !