I do agree that they way they do it is tremendously sh--ty. I assume they do layoff day this way so nobody can say they were singled out, and that it's a corporate decision and not a personal one... but the psychological effect of "sit in your office and wait to hear your fate" is beyond cruel. I know a few folks who got zapped and just used the opportunity to hop over to another role in a different part of the company where their skills and/or interest matched up. That might be getting harder to do lately, but it's still a valid option.
Sometimes you get stuck on a dog of a project, and your manager has no idea what value you bring, and you just get chewed up by the machinery. I've seen it happen to a good number of co-workers over the years. The ones who have been keeping their skills up-to-date and have built a network of contacts will be mildly inconvenienced as they move into their next role. The only way you're f---ed is if you counted on your job to last forever and never bothered to learn anything outside of your bubble.