If it is in the stitching are you then wearing a beacon that can be used for targeted advertising, data harvesting, etc?

Yes, you are. Most of the tags (the cheap ones) wear out after a few washes, but some do not (the expensive ones). And the expensive ones will eventually become cheap. I worked on commercial tech a while back that can scan these tags. And I built a smart home dashboard that does this to track wallets, phones, car keys, my cats and my dog within my home. Tags embedded in pet collars and wallet linings.

I also wrote a prescient short story, titled "Smart Furniture", published 20+ years ago, where the protagonist's day job was driving past people's houses to scan the tags on the interior, and he considered himself "better" than those folks who stood around in malls scanning the clothing of people as they pass by and accosting them with special offers. The ultimate form of "browser fingerprinting" in a way.

“Honey, why are you microwaving your jacket?”

“I’ll explain later, dear.”

You joke but there’s been militaries debating forcing all brought in items be microwaved to avoid hidden electronics being inadvertently sent to a secret military location.

I’m mostly joking, but I can understand why some entities would be completely serious about it.

You can already do that with google ads. Your google apps and devices report your location. You can join various datasets on who purchased what and when.

Google themselves has ad offerings making this fairly easy.

The RFID tags are on a sticker, you can see it on the back when you take it off.