Experts believe that the quality you can find at traditional thrift stores appears to be declining.

"If you go to a local Goodwill, you will see a lot of fast fashion there, sometimes with the tags still on," Nicole Craig, a professor who teaches merchandising, trends, buying, and more at Arizona State University FIDM, told Business Insider.

"But at the same time, we're also seeing thrifting and resale exploding in the market."

While an abundance of fast fashion is partly to blame for the decline in quality at thrift stores, the explosive growth of the resale clothing market over the past decade —especially in the last five years — has also played a big role.

The value of the global secondhand clothing market is expected to reach $350 billion by 2027, according to a 2023 report by ThredUp, an online marketplace for used clothing.

Part of why buying used clothing has never been more popular is Generation Z.

In the past, Millennials tended to appreciate uniformity and with that, new goods. Think Abercrombie & Fitch in its original heyday around the 2000s.

However, Gen Z is more focused on individuality and finding pieces that are different from what everyone else is wearing.

Gen Z has also embraced secondhand as a means to help the environment. The ThredUp report showed that sustainability was among the top five motivators for Gen Z when it comes to how they acquire apparel.

When secondhand shoppers feel like they're saving something from ending up in a landfill, buying used clothing is no longer viewed as inferior to buying new.

Thrifting today is "not only not a stigma," Craig said, "it's a badge of honor."

But even as thrifting has grown in popularity, so have fast fashion brands.

"It's not designed and constructed to last," Elena Karpova, a professor at the University of North Carolina at Greensboro who researches sustainability in the apparel market, told about fast fashion to Business Insider.

"And so after a couple of washes, usually either fabric or construction, like seams and stitches, fall apart, and people then discard it or donate it."

Some fast fashion pieces are so inexpensive that shoppers won't bother returning the ones that don't fit. As a result, piles of fast fashion get dumped in donation bins with their original tags still attached.

Prices at thrift stores have also been rising, partly because some people are reselling their "thrift hauls" at a premium on platforms like Poshmark and Depop.

These sellers have been branded as "scammers" by some on social media and compared to landlords who drive up rents and force people out of affordable housing. One could even call it "the gentrification of thrift stores."

People who still prefer the experience of shopping in person and stumbling across a surprise score are increasingly turning to curated vintage shops. Craig said many of her students who thrift weekly "prefer to go to some of these more curated thrift stores where it's a little bit nicer, it's a little bit more of a point of view." So as time goes on, gems like the ones we see in the pictures can become rarer and rarer. Let's enjoy them while it lasts!