I barely know the streets I take to my office, 6 months in (and I'm not just talking about their actual names). I use nav every time. My father thought I was losing my mind.
But at the same time I can remember basically every small block of code in a large saas I single handedly built a few years ago, even today.
Not exactly the case when you have ADHD.
No bullshit content, no doomscrolling, no ads, no notifications.
Trying to replace that with something useful here at the moment. Much more difficult than it looks.
Advertising wouldn't exist if we actually had control over what we pay attention to and memorize.
I get your point that a lot of knowledge acquisition that goes into short and long term memory has more to do with the environment (passive learning) and less to do with intentional learning.
Blocking the input entirely will always work (using headphones, not reading certain things).