No it doesn't usually, usually they agree to do stuff and if they don't agree everyone goes their own way. Usually there is no command in the friend group.
I disagree, and it seems to be because we're using the term "hierarchy" differently.
In my primary local friend group, the leader depends on the topic. If we're talking about the areas where I'm the (informally) recognized expert, I tend to lead the discussion. If it's someone else's area of "authority", they lead it.
Either way, while no one is designated at the person who decides what we all think or what to do, the person leading that conversation tends to have a heavy influence on the outcome and is responsible for building consensus.
That's a hierarchy. It's not a coercive hierarchy, but it's a hierarchy nonetheless.
This distinction is important especially when speaking to someone who is opposed to anarchy as a concept. Without it, they tend to see the (usually hypothetical) structures that we propose as evidence of anarchism's flaws. They're not - they're nothing more than thought exercises. While anarchists see those as a tool to help refine their view of how a system _could_ work, non-anarchists see them as evidence of internal inconsistency.
"Hierarchy" comes from "heira", which means "sacred rites". So it's "the rites which rule". In other words, "the process through which people are organized to do things"
To make it nice and confusing, "anarchism" has been applied to so many systems of beliefs over the years that it has no clear meaning on its own. To some people, it absolutely means "no structure whatsoever".
Etymology.com links:
hierarchy: https://www.etymonline.com/word/hierarchy anarchy: https://www.etymonline.com/word/anarchy