I have another suggestion which doesn't contradict yours.

When I was younger I used to get bored way more often. I had to wait regularly during a week (e.g. for a bus, friend, appointment) or even at work as a software dev (e.g. compilation which used to take more time). This was also the case when doing some physical activities which didn't require lot of thoughts.

Back then, before mobile phones with internet access, you were either reading something or alone with your thoughts in those situations. This was when I had time to think back at things that happened, processing the information I had, refining ideas etc.

Nowdays those are often situations where we ingest more information like listening to podcast, reading stuff on the phone, etc... or situations that just doesn't exists anymore having optimised our work to remove those waiting points.

I personally find myself with clearer thoughts when I break those habits and give my brain some time to be bored again.

I do think there is "lack of boreness" epidemic leaving people with way more raw thoughts and way less time to process and challenge information, leading to some form of exhaustion and lack of clarity.

I doubt that's the only factor, but I agree that it's almost certainly a factor. The modern "tech" industry has filled our waking hours with unceasing demands to do something. Buy this product, watch this video, listen to this podcast, react to this social media post; even "practice self-care" has somehow turned into an obligatory virtue-cultivating task. We obviously had advertising before, but this is a different beast, something akin to living in a casino.

As Bo Burnham put it, "apathy's a tragedy and boredom is a crime".

That seems less likely then people being tired and stressed from the costs of living and the increased economic instability.

We have smartphones but we're perilously few missed pay cheques away from not having a house, with a capital class gleefully telling everyone how they'll all be unemployable very soon.