I had an ex friend who only ever bought me one nice and thoughtful gift which I still have. Most the time I got a random assortment of things that I’m pretty sure were regifted including a partially used bath bomb

that she tried to claim must have “disintegrated in the post” but the other half was not in the box.
I caught her out once as she gave me a purse which I thought was weird as she’d given me a one the year before that (it was truly
weird: made up of laminated pieces of newspaper weaved together with a zip that didn’t close so also pointless).
The second purse was a really old fashioned looking thing and had a strange smell - musty but floral like it had been kept in the back of a wardrobe and then febreezed! When I unzipped it there was a Christmas tag inside saying “Merry Christmas (her name) got you this as you said you liked mine love Nanny (her maiden name) xxx” and then in brackets (Christmas 1994). Imagine regifting someone a present from your dead Nan that was (at this point) over 20 years old!
That wasn’t the reason we are no longer friends but I am sure you can see why we might not be given behaviour like that.