I wonder how common the inability to do it is in people whose native language is one that contains the trilled r. It seems that people who are raised speaking those languages develop the ability to do it at a young age so it's less likely they'll have a problem with it.

But then again I pronounced r's like w's until I was practically 10. 🤔

They probably don’t speak Spanish fluently or didn’t learn it as a child and simultaneously with their primary language.

Practice makes perfect!

I grew up speaking Spanish, so they just roll off my tongue 😁

I cant

Genes

I prefer to roll my K's

I grew up with French-speaking grandparents, so the “r” is very different, almost like gargling it. I just can’t roll my rs properly. My sister, who has a better ear for languages can speak both, but even she fudges the Spanish r a little bit, because she also spoke French first.

because many don't give it a shot. they just give up

Because you didn't learn to do it when you were young and your language skill were developing. You could learn to do it but it becomes difficult to train your tongue in adulthood.