Brain fog is nor good, nor bad:
Brain fog fueled with anxiety is likely a cause of prolonged anxiety, hypervigilance, excesive worrying, compusing consuming, etc. Practice letting it go, or not giving a fcuk. Go and get a small pint of beer in a pub when you feel unease. Find a cause of anxiety and tackle it. But its normal to have anxiety for brief periods, we live in a crazy world.
Brain fog not fueled with anxiety, but rather slow thinking, maybe slight fatique - is a blessing and normal state for relaxation. Enjoy it, we are not built for being super rational, hyper vigiland, 100 percent awake full on individuals. These states are not permanent, just like brain fog. But if you resist it, then this might create anxiety out of nothing. Not good.
To add to point 1) Anxiety & brain fog can be caused by lack of stimuli varieties, causing sensory deprivation. We have 5 senses, make you you engage in them constantly. Spending too much time on screen, even with lots of stimuli will cause sensory deprevation. So need to bring varieties into daily lifes and breaking patterns.
To add to another to point 1) do one thing at a time inside your brain. Multi-tasking will fry your brain very fast, unless you are a women, then some say you more stamina in this department.
To add another to point 1) close communication channels which are open ended and do not have any closure, this will create digital boundaries. When you ready to write to someone, or to receive from someone, open them up. But do not allow instant notifications. (e.g. work slack, phone notifications etc.)
Technical choices I have made. Its up to you if you want to take it to your bank.
Use windows 11, not windows 10. And you can add your choice of tweaks. Windows 10, although feels like back to normal, causes more brain fog than 11. Unless you have some sort of driver issue with it.
Appple silicon Airs are shait. No matter if you on external panel or not. There is nothing you can do. It will always be worse than other options. The more you use them, then more you risk of having anxiety based brain fog.
And last but not least - focus is NOT tunnel vission! Tunnel vission focus is misleading and can be more of a sign of addictive fixation than a healthy focus. It is unsustainable and will cause issues. Healthy focus always involves peripheral vision.