Lots of these cards have special art but the normal frame, or maybe a retro frame, or perhaps a special foiling over a normal frame
If you sit down to build Nahiri, Forged in Fury, you could build a really strong deck without much effort
if you have a commander like Baylen, the Haymaker that provides card advantage, you can get away with slightly less card advantage in the 99 then youd need with a commander like Alela, Cunning Conqueror or Mr
The downside of these cards though is lots of playgroups really don't like these cards so it's rude to play them at those tables, and also their win% goes down if your opponents both hate these cards and know you run them since they will gang up and kill you (ignoring everything else) so you don't get a chance to cast them
Fly, you fools! he cried, and was gone
Together, these bans foster an environment where a wide variety of decks can succeed