Well, it all comes back to how you define smart then, doesn't it?
It requires a pretty high degree of intelligence to create the type of technology that would allow a species to destroy itself. But, you could argue that it isn't intelligent to make technology that could destroy your species. But, then I could argue sure it is, you just have to be smart enough to use it for good. But, then you can argue that eventually, some bad actor can get a hold of it. This can go on forever. Who's right, both?
The Einsteins, Da Vincis, etc. making those breakthroughs are very smart. They are the objectively smartest organisms we know of to ever have existed. It is a fallacy to claim that "humanity" isn't very smart, simply because a lot of of the less intelligent humans apply the work of some geniuses improperly.
It takes 200 IQ to make the nuclear bomb, but 70 IQ can launch it. Humanity has a very WIDE range of intelligence.
There really isn't much of a reason to try to judge humanity's intelligence as a whole. I see nothing to be gained from denying the objective fact that we are the most intelligent life form, both by peak and average measure, that we currently know of.
The jury can consider a different verdict if and when we annihilate ourselves.
actually stupidity.. same as overbreeding.
define good
it could be anyone else. they literally where there at the right time building up from previous research. this is always how it goes. if it wasn't them discovering it, another fellow a few months later or before would. We build little by little on these things much like RNA builds our DNA.