This is particularly so of the speech of younger Americans. It goes hand in hand with 'and stuff' and speech such as ..."and he was, ya know, kinda gonna, ya know, buy this car...but then kinda, he sorta changed his mind, ya know, and...
It's possible to be casual in one speech without being inarticulate, or too formal, as 'rather' can sound at times eg
The pace of the baseball game was fairly slow/ a bit slow. Colloquial without sounding slovenly.