In my org, a Tech Lead usually worked more closely with Product and Engineering Managers than any other developer. The Tech Lead's primary job was to help Product break down tasks and make them more technically feasible. The management usually elected Tech Leads mainly as a way to give raises, but often the individual would use the spotlight to act as an envoy between Product and their team when the team lacked an Engineering Manager or the manager lacked competence (more common).

The Tech Lead role, in my experience, is a confirmation of execution and aptitude (in the eyes of management), but certainly not a certification of technical competence. Many teams had Tech Leads who were not as capable or as key of technical contributors as others on their team.

Across orgs, my experience is that Tech Lead is always a social spotlight and is only mildly correlated with technical competence. Tech Lead is much closer to junior manager than senior engineer.