Retro8 - what would have been the ultimate 8 bit micro?

Why 24 bits, 20 bits was all you neeeded in the era of 64K drams.
The undeveloped 65e4 claimed to be the ultimate mico, but I am having
problems reading the pdf. Ben.
PS: R65F11 (6502 ish) had FORTH kernal built in rom. Is that a Forth
cpu? or 6502?