I didn't say you should be judging performance solely on daily syncs, but you have a myriad of ways of doing that as a manager including simply looking at the big-picture content of PRs, what issues a dev identified and solved, what devs contribute to discussions/technical solutions in slack/meetings, what projects are completed, and how well they turn out etc.

But eh? Doesn't matter how loud you are in a sync, you can very easily go off the actual content of what someone is saying. If someone goes off 5 minutes about how they managed to turn an object into a json string, that doesn't exactly make them look good.