I stopped drinking 10 years ago and noticed no change. Did not lose weight, did not improve cognitive ability.
I wonder if all these reports of various changes for the better after stopping drinking (moderately, of course, not talking about people with alcoholism problems) are just placebo effect or it's that people's bodies work differently and for some people a few beers or wines a week may be a big deal whereas others are unaffected.
I wouldn't be surprised if that's part of the problem; some families I know consider a glass or two of wine with every dinner to be "moderate". Every Saturday and Sunday involves at least two bottles of wine each of those days, and it's called "moderate".
If they stopped their current habits I would not be surprised to hear that they saw a marked improvement in their health metrics.
I call myself "moderate", and have maybe two or three drinks per year, and never more than a single drink per occasion. I would not expect to see any improvement in my health metrics by cutting that out.
I obsessively track everything I can, what I eat (https://cronometer.com/), how I sleep (https://apps.apple.com/us/app/autosleep-track-sleep-on-watch...), my exercise stats (apple fitness/health).
Nights that I have alcohol can easily be seen in my sleep tracker (I fall asleep easily, but then have a very disrupted night of sleep). In my food tracker (Excessive carb intake). And in the fitness tracker (higher average heart-rate with lower distance/weight)
Improved circulation?