I am pleased that my post got you thinking Jenn! We are all in different positions with climate, work, home life, social life and preferences.
For me, in a temperate climate I feel my closet size is about right although ideally I would probably have a couple more sweaters and pants and a few less occasion pieces and tops. But I work from home, don't go out to dressy places all that much, and my size is pretty consistent.
I included footwear and that is one capsule that is working pretty well for me. I have good options for casual, active, formal, work etc.
At 45 years I have accumulated slowly - aside from thrifted pieces I have a wool coat that is 15 years old, a dress the same, shoes the same, and many pieces that are 7-8 years old. I have about five smart work looks but I only need to wear one or two a week, so I don't need a lot of variety here.
What I am not happy about is the shorts I gifted away that I had for one season and no longer like (but are in good condition), or the work trousers that never really were a flattering fit and were too short. These were poor buys and should not have entered the closet.
I only have tracked wears when doing a challenge, but intuitively I know my blush sweater, my grey merino and my Underarmour hoodie get worn an awful lot, at least once a week, usually more. But there is a black sequined merino sweater that has been worn one time this winter, and a grey striped knit that I am heartily sick of wearing. The sequin merino is a pretty layering piece but does not work with many other pieces, and the grey striped knit is good for slobby work from home days or popping on in the evening as loungewear. But we all have new favourites and the odd item that is harder to wear.
And my maths is dodgy. I have about 10 scarves (2 new to me this year as gifts, lots of costume jewelry (I think 3 being new this year) and a full large drawer of running jackets, sports tees and tanks, shorts, tights, swimsuits, rash tops etc. There would be 25 pieces in that drawer alone!