can-someone-explain's journey

I've been experiencing a frustrating pattern during my job search lately. I've had around five interviews where I've been completely ghosted afterward. Some of these interviews were multiple rounds, and in a few cases, the companies even expressed interest in hiring me or promised to update me by a certain date, but then I never heard back. I'm starting to wonder if I'm missing something in this process or if this is just a common issue. It feels particularly unprofessional to leave candidates hanging after they've invested time and effort into the interviews.