Nah, by having in-memory versions of your dependencies, in-memory versions which fulfill the same interfaces as those used in your E2E tests (or the majority of your E2E tests) you unlock running your entire E2E tests suite in milliseconds-to-seconds instead of minutes-to-seconds. And because they're E2E tests that work with any implementation, you can still run your exact same test suite against your "real" E2E dependencies in a CI step to be super sure both implementations behave the same.

I've done this across multiple jobs, and it's amazing to be able to run your "mostly-E2E" tests in 1-2 seconds while developing and the same suite in the full E2E env in CI. It makes developing with confidence so fast and mostly stress free (diverging behavior is admittedly annoying, but usually rare).

I highly recommend using these if feasible.