Positions are better than titles for that. Compare "Principal Engineer" with no other info to "Software Engineer, Lead at Mobile UX".
You know if they are your boss, not how big of a boss they are. That's way more important unless your organization is a chaotic mess where managers feel like they can order around people from a different team. And then you got bigger problems.
Sure but that's just adding more rather than different information really?
Like if the title is Tech Lead, Staff, Principal or whatever there's an (often) unstated focus area. You're saying if you also state that, that's helpful. Yes it is! But if you only state that – Software Engineer, Mobile UX – it's helpful but you're back to having no idea of relative experience or decision-making power.
(If the org is truly flat and the intention is no inequality in 'decision-making power' etc. then fine, I suppose, but that's kind of a different conversation, pretty unusual, and I'm not sure how much I really believe it works (as in, is borne that way) in practice.)