Are strictly indoor cats more friendly? 🐱

Melody
I've had many cats over the years that had the freedom to live indoors and go outside since we lived in the woods. I noticed that in general, once the cats are old enough for them to go outside, they get less cuddly. Only one of my cats has been an exception to ?
Some of my friends have strictly indoor cats, and they seem more people friendly. Is there something about the outdoors that makes kitties more 'wild?' 🐱🐈🐱🤔