My DH wears mostly polo shirts and tracksuit bottoms or jeans. He will wear things until they apart unless I intervene. He owns two suits: a dark one for weddings and funerals and a light linen one (which I bought) to take abroad on holidays or for less formal occasions. This winter he has been wearing an anorak/parka type of thing; in my view, this should be consigned to the recycling bin (I would not even consider taking it to the charity shop) but he says it is lovely and comfortable and perfectly fine; he has a good, knee length coat that is just right for the weather, but he doesn't wear it. Don't ask me why!
When my DH started teaching in ’71, male teachers were expected to wear a suit and tie. The dress code in schools is a bit more relaxed now, but he always went to work in a suit, so now that he is retired he just wants to dress casually.
I suppose I was always attracted to casual dressers… A long, long time ago I had a boyfriend who was the opposite: he liked expensive shirts and suits and always wore a cashmere overcoat in winter; but I left him for a jeans and t-shirt man! Well, I have nothing against casual dressing. Your clothes should be comfortable and suit your lifestyle. But I like quality, I don't wear things until they fall apart, and I like to dress up when I go out. As for my DH, he will wear the same thing to go to the shops and to go to a restaurant.
However, I do agree that you must pick your battles carefully and I have learnt that it is not worth making a big song and dance about what he wears, because he is not going to change...