The problem is not that a particular library, framework, or app is slow. The problem is the mindset "This is the best performance possible". Having that mindset

The problem is not that a particular library, framework, or app is slow. The problem is the mindset "This is the best performance possible". Having that mindset makes you accept extremely poor performance even when it is not economically advantageous to stop optimizing. Even though I am personally frustrated at how willing users are to accept slow software; I do recognize that the velocity and comfort of development outweighs the performance considerations in many cases. However, a mindset that makes you never check to see if the performance considerations are worth it to the users WILL make you make the wrong decisions.