First off, there are plenty of accounts that follow well over 500 people that are real (and they have literally millions of followers so its obvious that people know he/she/they are legit) Use a number more like 1000.
And the second thing, by proof of concept/definition, botting cannot die. Botting is simpy using code to advertise yourself in a more unique way without paying IG for it. For you to say botting is coming to an end is like saying advertising is coming to an end. I 'advertise' my account to 600 people a day. On average, 200 choose to follow me. That's all there is to it.