In my experience, many in-ear earphones don't have enough "grip" inside the ear canal and they still rely on that "bump" in order to stay in place. I'm talking

In my experience, many in-ear earphones don't have enough "grip" inside the ear canal and they still rely on that "bump" in order to stay in place. I'm talking about the ones that have a soft rubbery tip, I've never tried earphones with memory foam though.