Why do some discontinued Rolex models keep trading above retail years later?...

https://wiki-quicky.win/index.php/Box,_Papers,_Service_Card:_What_Should_I_Gather_Before_Selling_a_Rolex%3F

Why do some discontinued Rolex models keep trading above retail years later? Take the Kermit 16610LV and the Hulk 116610LV—both have built steady demand despite being out of production