Former TLM that was involuntarily reclassified as an EM because I had too many reports. I'm from old-line (pre-2011) Google, so was an engineer back when the TLM role was one of our unique competitive advantages.
I have a lot of thoughts on this. IMHO, it's appropriate for the state that Google is in now, where it is a large mature conglomerate, basically finance & managerially driven, built around optimizing 10-K reports and exec headcount & control. It's not a particularly good move from the perspective of shipping great software, but Google doesn't really do that anymore.
The reason is because software construction and management is unintuitive, and concrete details of implementation very often bubble up into the architecture, team structure, and project assignments required to build the software. TLM-led teams have a very tight feedback loop between engineering realities and managerial decisions. Your manager is sitting beside you in the trenches, they are writing code, and when something goes wrong, they know exactly what and why and can adopt the plan appropriately. Most importantly, they can feed that knowledge of the codebase into the new plan. So you end up with a team structure that actually reflects how the codebase works, engineers with deep expertise in their area that can quickly make changes, and management that is nimble enough to adopt the organization to engineering realities rather than trying to shoehorn engineering realities into the existing org structure.
Now, as an EM with 10+ reports, I'm too far removed from the technical details to do anything other than rely on what my reports tell me. My job is to take a slide deck from a PM with 10 gripes about our current product, parcel it out into 10 projects for 10 engineers, and then keep them happy and productive while they go implement the mock. It will take them forever because our codebase is complex, and they will heroically reproduce the mock (but only the mock, because there is little room for judgment calls in say resize behavior or interactivity or interactions with other features and nobody's holding them accountable for things that management didn't have time or bandwidth to ask for) with some hideously contorted code that make the codebase even more complex but is the best they can do because the person who actually needed to rewrite their code to make it simple reports up through a different VP. But that's okay, because the level of management above me doesn't have time to check the technical details either, and likewise for the level of management above them, and if it takes forever we can just request more headcount to deal with the lack of velocity. Not our money, and it's really our only means of professional advancement now that product quality is impossible and doesn't matter anyway.
Ultimately the value of the TLM role was in that tight bidirectional feedback between code, engineers, and management. As a TLM, you can make org-structure decisions based on what the code tells you. As an EM, you make org-structure decisions based on what your manager tells you. But at some point in a company's lifetime, the code becomes irrelevant - nobody reads it all anyway - and the only thing that matters is your manager's opinion, and by transitivity, your VP's opinion. A flattened org structure with as many reports per manager as possible is a way for the VP to exert maximal control over the largest possible organization, mathematically, and so once that is all that matters, that is the structure you get.