The Ryzen 7 9800X3D may have just launched, but AMD doesn't expect an end of life announcement for the old 7800X3D 'anytime in the near future' and 'would expect it in the market for a while'
I have one and it's still obviously fantastic for gaming. It wasn't even that long ago I bought it, I'd sure as shot hope its not end of life'd for no reason.
AMD essentially keeps AM4 alive because 8 core CCDs dont make it easy to have a budget oriented options, something intel still can do (e.g low end i5s and i3s) due to at the time, monolitic design. yields on 8 core ccds are soo good that even 6 core ccds are fairly limited in numbers. and would be financially impractical to disable 4.cores intentionally to make a 4 core option.