Where do stolen bikes end up?

So, I've been following this story over the last few days ...

https://road.cc/news/stressful-but-also-uplifting-ultra-cyclists-bike-returned-to-her-days-after-it-was-reported-stolen-from-leeds-petrol-station

TLDR - the female winner (Justyna Jarczok) of the Dales Divide over the Easter weekend had her gold Kona FS bike stolen from outside a petrol station in Leeds, on her way back to her hotel after she'd got the train back from the finish of the ride, and before her flight back to Poland.

I picked up the story on Instagram, and as the petrol station in question is quite close to me, popped in to see what they had to say (basically, "we have the CCTV footage in which two guys on a (presumably) e-motorbike came past and grabbed it, but can only let the Police view it") and then emailed the local councilors to see if they could bring any influence with the Police (to be fair, they did, but the PCSO was sent round to view it at about the time Justyna announced the bike had been recovered!)

I'm not sure how it got recovered; I understand someone saw it advertised, bought it, and then the cycling community (including Restrap) reimbursed the buyer and have arranged the return to Justyna.

Anyway - the whole series of events made me wonder what happens to stolen bikes, and where do they go?

The answer usually trotted out is eBay / Gumtree / FB marketplace etc ... But in all the incidents of 'stolen bike' alerts where I've actively looked to see if they pop up for sale, I've never seen them advertised.

So, there must be a black market for this sort of stuff? Are there trading / selling platforms on the dark web? I'm sure some of it - for higher end stuff - is organised crime, and stuff potentially being shipped overseas? Are bikes stolen to order? Is there a community of keen / enthusiastic cyclists that are after fancy road bikes and MTBs, and don't care whether they have been stolen? Is there a network of traders/shops that fence this stuff?

Why don't we as a cycling community have more knowledge or intelligence collectively about what's going on? As it seems that every time someone posts up eg on here, social media etc to say their pride & joy(s) has/have been stolen, it's almost a hopeless appeal as though they're resigned to never getting it/them back?