This is something I've been spending a good amount of time thinking about. The fashion / textile industry has changed dramatically over the past fifteen+ years. Clothing has remained about the same price but, (see: shrinkflation) the quality of garments has decreased per dollar. It's actually amazing that you can walk into a Target and spend $25 on a really decent t-shirt and a half-dozen pairs of socks.

How long your garments last depends largely on your activity level and how often you wear and wash them. It also depends on what materials they're made out of. Fabrics made from plastics (practically everything) are not going to last as long as those made from natural fibers - assuming they're cared for the same way. A lot of cheaper garments are made with thinner fabrics or assembled with poor stitching.

So, where you get your clothing, what you spend on it, how you maintain it, are all going to contribute to how long it lasts.

Honestly, I work from home so sometimes I'm wearing the same clothes for two to three days if the weather's cool and I'm not seeing anyone. These clothes, regardless of material, are going to wear out sooner than the nicer clothing I wear out of the house and on weekends.

Any time I buy new clothing, I check to see what materials are used. I try to get stuff that's made of 100% cotton or wool or canvas, etc. I've been getting my t-shirts from Solid State in NC and most of my sock are made from hemp or alpaca wool. I have one pair of decent Levis jeans that I've only washed once that are over ten years old.

Upfront, I'm spending more. In the long run, I might spend about the same in total on clothing but I'm producing much less waste along the way. I rather spend more money on something decent I can wear more often and have a smaller wardrobe.

To answer the question - if I were to lose 25lbs to fit in some older clothing I still have, the rest of my life, easily.

The only exception to this is shoes. I go through shoes way too fast (<3years) and they're all trash now.