They're quite different product lines, serving different markets. The heatsink you'd need to cool something like the 9800X3D would be the size of the Mac mini itself. The Intel Core Ultra 9 285K costs roughly the same as the entire M4 mini, has twice as many cores (4x as many threads), and its advertised base power is twice the M4's maximum.
There's nothing wrong with comparing them, but they don't seem to be in the same market.