From the perspective of the dev, if my local CI isn’t worth anything towards a merge and upstream CI is gospel why run locally? If I’m reasonably certain that the two jobs are duplicative in output it could be seen as wasted time, especially if I have a PM hounding for features. I don’t call that lazy, I call that a trade off. (coming from someone who is constantly running tests locally before pushing upstream)

Isn't that slower and less efficient? Usually the CI has to run a full build from scratch before it can run the tests, but locally for me it's going to be an incremental build that takes a second or two. I can also run the subset of tests that I know are affected by my changes to get fast and reasonably reliable feedback vs waiting for CI to run the whole test suite.