A lot can be learned from that observation.

It is a human flaw.

The more a specific person stands out above average, mostly in just one specific topic or expertise, the bigger the ego gets.

If it is allowed to continue for some years most people get so used to being smarter they start to think they are just better in most other things as well.

Since they are smart they don't fail often even in the fields they are not an expert in.

Their status of being above average makes most hold back to argue the 'smart' ones.

And so they fall to the God syndrome.

They think they know everything better.

They start having opinions about everything even the fields they have no real knowledge about.

All arguments of others are dismissed by default because others are not as smart as they are.

The bigger the difference between those smart asses and the average the blinder it makes them.

They get to positions in big companies or government where they have way too much power and can start destroying things without much opposition.

Some surf in their slipstream by just saying "Yes you are right".

Others know not to argue as it will ruin their career.

That are what I call "smart but dangerous people".

There are too many of them.