Here is a list of the biggest changes I've experienced over the last six months.
Junk media gives me insomnia. My insomnia always goes away within 1 week of abstinence. The problem has not returned during 6 months of abstinence.
Even without insomnia, I tend to go to sleep around 2-3 am and wake up around 11 am. I predicted (incorrectly) that long-term abstinence would bring my circadian rhythm closer in line with the day night cycle. This has not happened.
Before this experiment it took lots of willpower to study things like physics. I have a longer attention span now. I relax by training skills and learning things.
I had to stop studying quantum field theory because it has become too addictive. This vice appears limited to theoretical physics and junk media. No other subjects have triggered such intensity of addictive behavior.
Theoretical physics aside, I like getting smarter by default.
I have a garden. I walk more. I write a lot. I cook good food by default. Though self-employed, my productivity at work remains unchanged.
Abstaining from junk media seems to increase my socialization from "almost none" to "a little bit" but it's hard to tell due to the confounding effects of COVID-19. Socializing makes me happier.
When I begin abstaining from junk media I usually get a small bump to my tidiness. I predicted (incorrectly) this effect would become more pronounced over time. Instead, my tidiness returns to baseline levels as I acclimate.
The common thread is lower overall stress. I have lower overall sympathetic nervous system activation. This could be the root cause of my lengthened attention span and reduced insomnia.