There used to be a lot of software engineers (people on the software engineer job ladder, as opposed to the engineering manager job ladder) who had 2-3 people reporting to them and were considered TLMs.
I didn't know about this in google... and that sounds truly inefficient. A tech lead (or staff or principal engineer or scientist above them) is not supposed to be a front-line manager.
And a front-line manager is not supposed to be acting as a tech lead (at least not most of the time.)
A somewhat imperfect way of seeing this is that a tech/staff/principal lead/engineer or scientist acts like a corporal or sergeant whereas a front-line manager acts like an LT or captain. Leads are in charge of giving technical direction and mentoring.
They are operational. Managers (starting with front-line managers) are in charge of providing the general direction to meet the department, project or company's objectives, and ensure the engineers and tech leads under them are equipped to do the job.
To mix both roles, in particular when there aren't that many people to lead or manage, that's just a recipe for inefficiency. In small companies, startups or with skunkworks, this is both unavoidable and sometimes desired.
But if that's the general pattern across the board in a large company, that's just organizational cancer IMO.