> I still don't know why all the clothing suddenly developed that smell - I went my whole life without needing to do anything special to my athletic clothes until then.

It's the takeover of synthetic fibers (i.e., plastic) for everything, but especially anything athletic. Damn near everything is 100% synthetic, not even a cotton or wool blend anymore. From the high end to the low end, all synthetic.

I experience the same thing with any synthetic athletic clothes. They retain so much stink and it's so difficult to get out. And even using sanitizers the fix is very temporary and the stink comes back quickly.

I've switched to wool shirts for running and they do not have this problem. Unfortunately they are harder to find and more expensive, but so worth it for both feel while wearing and not retaining stink.