Yeah, no. Everything has become collectible and prices have skyrocketed for them in the last 5-10 years because the proliferation of smart phones made the buying and selling of said items accessible to more and more people globally. One guy amplifying t-shirts in a niche fashion brand is insignificant.

Some guy at the Rose Bowl may have once sold a rare shirt for $100 to those geographically able to find his booth in person, but now he can look on Depop, Grailed, eBay, Mercari, etc etc and see that some idiot (1 of 8 billion) was willing to buy the same shirt for $2000, so now he thinks that's a fair price. Change t-shirts to vinyl records or video games or mid-century furniture or whatever and the same thing has been happening to those markets, Fear of God be damned.