For me the cost is much less about, "It's just a few minutes long" and much more about, "Having to get up from my desk and talk to people about their projects kills my flow state." It's a short meeting but it's still a meeting and has the same effect on focused thinking as a longer meeting. Losing focus is totally fine if there's benefit to it, but for standups where I neither learn nor teach anything new, it's all cost and no benefit.

I too like knowing what my teammates are working on, but I already get that from the team's Slack channel where people talk about what they're doing as they do it.