It's always been said that watches should slip under a shirt's cuff.
I find my watches a lot of the time over my cuff, the cuffs are tight.
And simply watches are becoming thicker and biggers.
Maintaining under-the-cuff etiquette is being difficult.
Is it still a thing ? Does it really affect one's appearance or we have to evaluate how watches wear given the changes in watches trebds from small ones to big ones ?
It's still common practice. The general idea is not to shove your watch in people's faces, but have it hide under your cuff as long as you don't look at it.
I have the same issue as you. Most cuffs make it hard to wear it like that. I can do it with a diver but it doesn't automatically slide under. I have to help it a bit. I got only one super slim quartz watch that makes "under the cuff" effortlessly with my wrists. Custom shirts would help but watches are already expensive enough. ๐
Maybe find a brand of shirts with bigger cuffs. Some online tailors (if you want to go that route) offer to adjust the left cuff to allow for room for a watch.
Or simply just go with the flow of all the people that wear a 55mm Garmin apocalypse watch with a dress shirt nowadays.