Bodybuilders lose muscle and they do a lot of hypertrophy training and high protein eating to counteract it. Probably the average ozempic taker does neither of those so they end up losing more
But fat people actually frequently have quite a bit of lean body mass - it takes muscle to carry around all that weight, even if you're sedentary. If I somehow maintained the LBM shown in my DEXA scan at the start of tirzepatide, by the time I got to my goal weight, I'd be looking more jacked than when I was lifting 3 times a week.
Obviously, I won't. I'm adding more and more cardio and lifting back in as my weight is dropping and it becomes more maintainable for my joints, etc., and I've been supplementing protein since the start, and I'm sure I'll still lose plenty. But I have the room to lose A LOT and still be in the healthy range of body fat%.
The idea that caloric restriction is causing all this muscle loss is one of the dumbest ideas we currently have.
It is simply not true.
IFBB bodybuilders getting weekly DEXA scans and running multiple steroids including cycles specifically designed to help prevent muscle loss during cuts still lose muscle mass when losing weight for shows, despite taking every drug under the sun, working out an obscene amount, eating huge amounts of protein.
Your body will break down muscle when losing weight. You can do a lot to prevent the vast majority of it, but there is going to be some no matter what you do.