The idea that something is being wasted before it makes it to the bin hadn't occurred to me. Of course I had heard bits and pieces but it hadn't sunk in.
We have to look at 3 stages of the garments life, how they got to us, when we have them, and where they are going when we finish with them,
When we have too many clothes it means that things go out of fashion, or get too small or we go out and buy a better version of them before we have a chance to wear them (enough), and eventually we end up throwing them out. They are already a waste, even though they are not technically in a bin, if they are sitting in our wardrobe nobody is able to get any use out of them.
The kind of things that were wasting away in my wardrobe (some of them I had left behind when I went away for 2 years some of them I had carried with me (out of guilt)) were:
A top that needed to be hand washed...I hardly ever wore it because of this, and then when I did it sat in the bottom of the laundry basket for months until I got around to washing it, which was such a scarring experience that I then left it for ages before wearing it again.
An expensive jacket, that was a bit to boxy for my style, but was expensive so I should keep it, even though I didn't really like it.
Then there was just loads of multiples of things, which I did actually wear and like, but I had to choose which one to pick each time, when really i would have been no worse off if I just had less of each. If one of them went missing for a few months I didn't even notice or miss it.
Each of those garments had required land, and water and poorly paid labour to be made, causing pollution from pesticides and processing and transport, so the more use that was gotten out of each either by me or somebody else...the better.
Another issue with having a big wardrobe is that you do more laundry, if you have 2 cardigans and you wear one for 10 minutes and then shove it in your handbag for the day, you are not going to put in the wash when you get home, you'll hang it up to be worn later in the week, but if you have loads of clothes, you might be temped to wash it as you wouldn't want to leave it for months without washing it. (this is probably an over cautious example...but you get the idea).
Another advantage of a smaller wardrobe is that if you are buying much fewer items you can justify spending more on them. Which means you can make more sustainable choices, because the total amount you are spending on clothes will still be much less.
So smaller is better, it means other people can be wearing the clothes you aren't, you can save on laundry and you can make better choices.
Of course these are all only the environmental reasons to have a smaller wardrobe, there is also the advantages to you!
The afore mentioned doing less laundry is one.
The fact that you can clearly see what you have and can save time and energy choosing what to wear in the morning.
With paring down your wardrobe you will end up with more stuff that matches, so it make you less likely to end up wearing something mismatched that you aren't comfortable with just because you made a bad decision in the morning.
You get to wear your favourite clothes all the time.
It is quicker and easier to pack for trips and you can travel more freely with smaller bags.
You don't feel under pressure to buy new clothes for events, resulting in less stress and saving money.
You have more space in your wardrobe making it easier to clean.
You get things fixed/cleaned quicker so you don't end up feeling guilty about to do lists.
...infact I am so uplifted by this list I just wrote that I am imposing another buying ban on myself for the next 3 months.