You're conflating two different things here.

TDD Is a very specific methodology where you write all your tests before the code. Very few places do this. I have attempted to do this in the past, but I found it was highly ineffective.

What you are talking about is automated testing - unit tests, integration tests, and that sort of thing. And you are completely right that any shop that doesn't use automated testing is not a fit place to work.

All my small libraries have 100% test coverage, just because I can. In real-world projects of size, 100% test coverage is usually a poor use of time but new engineers are always surprised at how many tests we have and how well in practice they cover the gamut of behavior.