I actually have Audacious, which scratches the itch pretty well. A clean-room implementation of Winamp running on Linux would be more for the novelty than anything else.
I use Audacious with winamp base skin, it give the nostalgic feel with all the cool music playing features :)
I came here to make the same suggestion but he's got a gitlab link. I might just take a crack at trying that myself.
Let me know if there is anything I can do to help! I recall it was hard/impossible to get non-rounded corners on MacOS.