558
So long, small phones
(www.theverge.com)
This is a most excellent place for technology news and articles.
I didn't try the S21, but I always thought the S8 was a very comfortable phone to hold. It was tall, but narrow, and very thin. I'm not sure I'd go back to that now, but I did like it a lot at the time.
The S21 is wider by a lot (71mm vs 68mm)
There are just a handful of flagship phones coming out in the last two years that are sub 69mm wide: the zenphones, and the xperia 5 IV and V (and the apple iphone SE 2022)