Very interesting video with Ian Cooper explaining the big misunderstanding around the word "unit" in the term "unit test"
He is saying that the word "unit" wasn't about the system under test (i.e., class, method, etc), but was about the test itself. "Unit test" is a test which doesn't depend on any other tests.
I think I was pondering the same idea when making the title picture regarding the test pyramid and it exactly the same reason why I was working on the Feature test model (https://aqaguy.uk/pages/ta/ftm/feature_tests/) which helps build effective test coverage disregarding of the approach you choose (test-first or test last).
What do you think? Do you agree with Ian's definition of unit testing?