Comment by antonvs

For a single person and their one-person code base, you can certainly get away without unit tests.

This is especially if your "integration tests" are testing the same component, and not actually integrating with numerous other components being developed by different teams - or, if the system is so small it can run on a single workstation.

Working in teams on larger systems, the situation is different. Part of the point of unit tests is the "shift left" which allows problems to be discovered early, ideally before code leaves a developer's machine. It reduces the time until bugs are discovered significantly, and reduces the impact of one dev's bugs on other devs on the team.