I use red dots on my target pistol, a Ruger MkIII and it's fine for that. However I have an astigmatism so I need the dot turned way down so it isn't just a random splash of red. Almost impossible to pick up quickly.
I've tried red dots that are on friend's carry guns and I'm not yet able to pick them up as fast as iron sights. Also my friends and I shoot weekly, doing basic CCW drills.
The guys that have red dots all have had the draw and no dot, more than once, guys who I know maintain their gear well. For whatever reason that dot wasn't on when they drew their gun, usually their first draw of the day from the holster. After that the dots are pretty reliable. The dots I've seen are Trijicon and Holosun and one other I don't recall. Two of the three guys have backup irons so it isn't a big issue, but it's an issue.
My iron sights are always on. So I'm personally not ready to switch to
red dot sight for carry yet check
site. Plus I'm not keen on cutting out a slab on any of my 1911s.