I have known 3 men who were circumcised as adults.
ALL THREE regret having the procedure.
Here in the US, it used to be nearly unheard of for male children to not be circumcised shortly after birth... I WAS!
Today (2021), in this country, it's about 50/50 - the times, they are a changing! Still, most parents who choose TO circumcise say they want their child to "be like their father" or "be like the other children"... to which I say HOGWASH
For one, as the father of 4 boys I can attest that as babies they're not equating that tiny little pee-pee with my much larger, hairy penis... and then, as pre-teens, teens, and certainly as adults, I'm not wagging my dick in front of my children! I honestly don't think any of my children has any idea that I am circumcised! (NONE of them are!)
As for young boys comparing penises, little Johnny is far more likely to care about whether his growing manhood is BIGGER or SMALLER than the others than he is about what the TIP looks like!
There are FEW legitimate medical reasons for circumcision, and some religious ones... but barring one of those, leave your pleasure palace the way God crated it! He did it right the first time, he doesn't need a touch-up!
Finally - the point about the 3 friends (well, 1 friend and 2 ex's): all three reported that sex (especially masturbation) felt VERY DIFFERENT after they were "cut"... not better, not worse, just DIFFERENT. (Again, all 3 regretted their decision to get circumcised as adults.)
YOUR MILEAGE MAY VARY but remember this: once you're circumcised, there's no going back!