I don't have kids, and I was never beaten as a child. I was, however, spanked on occasion. I can probably count on two hands the number of times.
I don't think spanking is abuse, but I also don't think it's necessary.
A spanking lasts under a minute, and then the punishment is over and the slate is clean. The child has not really learned that X behavior is wrong. They've learned not to get caught when they're doing X. I compare this to photo radar speed enforcement. I have had a few photo radar tickets. I pay them online in under a minute, and they don't really deter me from speeding. I just don't speed more than 14 km/h over the speed limit in areas where the photo radar vans are known to sit.
"Not getting hit" isn't really a child's currency. Kid currency is different depending on the kid, but includes things like video games, bike riding, stories, phone privileges, parental approval, weekly allowance, etc. My big lever as a kid was parental approval. Hearing my mom say she was disappointed in me was about the worst punishment I could get. It was worse than any physical punishment that my parents ever could have dealt me. I also didn't like being left out of things, so being sent to sit in my room to think about what I'd done while everyone else was in the living room watching tv or whatever was pretty rough for me, and I had a TV in my room.
Often when I see kids getting spanked, it's because the parents are too lazy to discipline them in other ways. A spanking takes less than a minute, but actually discussing the behavior with the child, then following up with making sure they don't play video games for the next week takes time and effort.
I also find the parents who do the most spanking are also the ones who focus on what the kid is doing wrong instead of guiding them into correct behavior. Kids aren't born knowing right from wrong. They learn it from their parents. Loving, involved parenting teaches empathy. Empathy leads to being concerned about how your actions affect those around you. Let's look at the "running around the coffee shop making a mess" example. If the parent smacks the kid's butt and tells them to "stop running around and making a mess", the kid only learns that he's not supposed to be caught running around and knocking things off shelves. If the parent stops the kid and says, "Hey now, these nice people are trying to enjoy their coffee, and the nice lady who makes the coffee doesn't want to have to pick all of this up. Let's pick it up, then go sit nicely in chairs and drink our hot chocolate", the kid learns that his behavior is negatively impacting other people, and has then taken steps to rectify (cleaning up). That would take more time and patience from a parent, but be more valuable to the child in the long term.
The final thing I'd like to say is that I think many parents put their kids in positions where they can't be successful. Children need sleep and good nutrition. If you deprive your 2 year old of his afternoon nap, then give him some candy to keep him quiet for a bit, I don't think it's really fair to then expect him to sit still in a cart at the grocery store and not be cranky and whiney.