The title has definitely been diluted by HR departments using it as a retention lever, but the industry standard still exists implicitly. I differentiate seniority by how a developer handles ambiguity. A junior needs a fully spec’d out ticket. A mid-level needs a well-defined feature goal. A senior can take a vague business problem ("our checkout flow is dropping users") and translate that into a technical roadmap, coordinate the team, and deliver the solution. That level of product empathy can't be rushed in 2 years.