$DFI (old $YFII) vs $YFI vs $YFV

What is the difference? I love $YFI and I know many have used their vault design (although they are releasing v2) and that Andre even encourages that but what's the pitch for something like $DFI? There are other competitors like $YFV as well? I believe the strategies get devalued if they're spread more broadly so what is the competitive advantage of $DFI money?