Downfall of his MMA career was also the biggest windfall of financial fortune for him. Crossing over to a boxing exhibition, starting up his whiskey line, and venturing into movies. Plus staying "relevant" by living up to his Notorious nickname by throwing tantrums and running afoul of the law as a thug and drunkard.
Good for him - bet then having the ego and audacity to think you are going to just step back in against guys that eat, sleep, and breathe to fight their way for a chance to sniff even a fraction of his success. And alas, now the constant tease that he will step back in and fight is more lucrative for him rather than to actually do it and get exposed as a shell of what he once was.