The ability to make yourself do something that you consider good but yields no immediate pleasure is real, useful, and can be cultivated.

No one denies that. The article argues that current "attention economy" tech is actively making this harder or even impossible.

Saying it's impossible is denying it...

No, he is saying, it's becoming impossible - and he goes on to argue why this is the case. That's pretty much the main point of the article.

What's your counter-argument?

I find this incredible unless the Evil Social Media Companies reach into my brain and remove my capacity for practical free will.