Some people have premium membership of different warez sites like psdly, gfxfather so they download from there and share here, some people share stuff they baught themself from original owner of the product and i guess there are some private torrent groups who share these leaks and as mentioned above whoever got the stuff which is requested here and isn't released here yet leaks it!
Either find someone who already has the leak and pay them less or go into discord groups asking for the leak then re-leak it on here, discord communities always have leaks too so you mught wanna check it out