The purpose is survival itself. Following someone's instructions is just one means to that end. Just like your purpose in prehistoric times wasn't just to hunt down and kill a specific wild pig.
This will probably be a very unpopular opinion but I definitely feel that men innately need this struggle.
I am, at least partially, via progressive inheritance tax.
Improving the chances for success for your offspring is an innate desire, removing the ability will affect people's motivation to contribute beyond a certain point. A tax on inheritances will allow you to improve your children's life while removing the wealth if a family chooses not to work for a few generations, thus motivating contribution beyond "I exist and I inherited money".
I dont think the majority of physicists or bankers are struggling to survive. There is more to life than survival. I think the need for struggle is better described as a need for burden, rather than survival. It opens up many behaviours that prioritize ideas above biological need to survive and reproduce.
Your opinion cant be removed, everything in life can be reduced down to biology if you accept to lose out on certain axioms.
This will probably be a very unpopular opinion but I definitely feel that men innately need this struggle.