TPM and TAM are completely different roles. TPMs are essentially project or program managers across wider parts of the org, and the "technical" means they have something beyond a surface understanding of the technical aspects, but are likely not writing any code. TAMs are account managers in the sales org with a focus on giving clients more technical support or planning integrations etc.

"Technical lead" is not a role profile or ladder, it's what you're doing. You could be a TL at L4 on a small project, and you could not be TL at L7 if it's a big enough project. All very subjective.

The point of this thread is that there are teams with a manager who is the defacto TL for the projects the team is doing, so they have IC responsibilities, and then there are teams where the manager does manager things and there's one or more separate TLs.

I've worked on teams in both structures, both in and out of Google, and whether TLMs vs EMs work well depends on so many factors: who the manager is, their management style, the org's priorities, the projects, etc.