GOOG has made a systemic push to eliminate the role starting ~3 years ago. At that time my M was a staff level IC TLM with 4 reports who was forcibly converted to EM.
In those last 3 years I've only seen TLMs used to assist an overloaded EM.
The pattern I've seen is something like:
Principal EM
|- Staff EM (7 reports, project A)
|- Staff EM (8 reports, project B)
|- Staff IC (projects A, B, C)
|- Senior IC (projects A, B)
|- Senior IC (project C)
|- Mid level IC (project C)
|- Mid level IC (project C)
Maybe project C was just reorged under the Principal EM or maybe it's a speculative side project. But those last three are clearly clustered, there's no good line manager fit and the principal EM feels disconnected from the 2 mid level ICs. Project C is a bit of an island and projects A and B are taking up most of the EM's time.
So the Principal EM deputizes Senior IC on project C as a TLM until things have changed enough that there can be a dedicated EM. Eventually the TLM converts to EM, a new EM is brought in, or there's a reorg, etc.
Of the two times I saw saw it happen locally, both converted back to ICs after a year or two and noted that the role felt like being 70% IC and 70% EM.
Nowadays the TLM role doesn't exist so the principal would delegate most of the technical responsibilities of the M role, giving them nearly full control of project C, but would not give them a formal role. (I've been that senior IC for project C.)
(Edit for formatting.)