I’ve found the opposite. I have older pairs of jeans that are a smaller waist size that still fit and newer jeans that don’t. Shirts, too. I’ve been “L” for decades, now it’s “XL” or the sleeves and shirt are too short.
IMO manufacturers used to pre-wash/pre-shrink their fabrics more regularly. Now they don’t. They can make more clothing by the yard with non-shrunk fabric. So as soon as that ”L” shirt hits dryer it shrinks. The XL shrinks to L. I verified this by placing two shirts, pre- and post-wash, and the size difference was obvious. Maybe some “vanity” sizing is going on, too, or just being cheap. I haven’t gotten taller, but the L size is too short now.