I personally feel like most inventions and successful business ideas started with a good purpose.
This. Almost all disruptive ideas, and startups, came from a specific pain point. A lack of something (FB) or an impossibly difficult way (Uber). Most of the disruptive startups became popular because they provided the user with a better, a faster option. They challenged the status quo.
That, eventually, accepted venture capital and greed of investors, who play a very dangerous game with their reputation and need to hint and capitalise on those few unicorns, would dominate the board room and thus often eventual poorly affect the further technological evolution is a sad, but also inevitable, outcome of popularity. Share/stakeholders want a return. The more they invested, the higher the return they want.