>and maybe "s/smartest/some of the smartest/g"

Not maybe, definitely. Unless you are trying to make the claim that the set of the smartest people in tech is a proper subset of the employees of Google (or Google employees unioned with Facebook employees). I think lots and lots of very smart people that don't work for Google or Facebook would strongly disagree, and evidence is on their side.

>lots and lots of very smart people are channelling their efforts into getting people to click on ads.

Yes, but lots and lots of very smart people are also doing <insert other kind of tech venture here>. The statement seems to pre-suppose that there is no or little value in the work they do and they should be working on more 'valuable' problems.

I personally hate advertising, but I don't look down on people that work at Google or Facebook if their job involves increasing click-through rates, nor do I believe having smart people focused on these kind of tasks is 'holding us back' in any meaningful way. To believe so implies that 'smart people' can excel/advance the state of the art for anything they work on, and thus they should focus on more 'important' things. If these smart people were attracted to doing these more important things that may be true, but then they would probably be doing them already. If they are attracted to what they are doing then they should continue, and do it as best they can. Further it ignores the idea that there are side-effects of their work that could be more valuable to the world as a whole (like new discoveries in machine learning, or algorithms, or even human psychology).

The fundamental currency that buys advancement is intelligence, creativity and passion for what you are doing. If you have 2 out of 3 you are unlikely to contribute meaningfully, and simply reassigning everyone at Google to work on say self-driving cars is unlikely to yield reliable, self-driving cars any faster, in fact it would likely cripple the effort.