So wouldn't it be relatively simple to block AWS/Azure/etc ip blocks AND duplicate accounts from single addresses? Wouldn't that be a large drop in bots right there?

Corollary: I once played a large MMO that intentionally inflated user numbers right before they were acquired via content updates that encouraged the creation of multiple bots per actual player. I'm sure at some level executives are aware that bots are good for business and allow them to persist.