Why haven't humans evolved to a better species?

This question just pops into my mind several times.Tell me what do you think about this,and if I m wrong?
Its been thousands of years since we humans, due to evolution, got differentiated from apes/chimpanzees whatever. Why haven’t we humans evolute to become some more better species than ‘HomoSapiens’? Thousands of years were not less for this,no?
We are just becoming better and better humans, maybe because we get our genes from both of our parents.Could this be because we are no more in ‘direct contact’ with nature? Because we have built houses,we have clothes,air conditioners,heaters etc. and in a sense have isolated ourselves from nature? And so we couldn’t adapt ourselves and evolve?
And I don’t see we humans transforming into some better species in future.Because we are not using our bodies to deal with nature,for example in summers we use air conditioners and in winters we use heaters and so on; so why should our bodies change? We may not evolve because we have stopped changing ourselves but the environment around us? Because we have reduced our interaction with the nature around us?