Adding to (1b): it's not just that companies will
ignore some aspects of the job description as posted. For some companies, that description isn't intended to represent the expected contribution of a single employee -- if you read between the lines, it might be a description of a new team or of a new long-term initiative. The company might post it as though it were a job opening for an individual out of laziness, out of ignorance of what skills are actually needed, or in the hope that one magical developer will be able to do everything on their wish list.
Ultimately the company will want most, if not all, of the listed skills covered. However, if you can convince decisionmakers that you can successfully start addressing a subset of their needs today, as `patio11 says, then the company may recalibrate their posting to find someone (or multiple someones) to cover the remaining duties or provide training to you (or to existing staff) to shore things up.
The lesson is not to take a job description at face value. Setting aside the fact that some postings are written by people who don't actually understand the role, companies will always try to hire the most talented people for the least amount of money, as they ought to. But if hiring that one mythical ultra-developer is "shooting for the moon", then hiring someone who can effectively make inroads into the company's growth areas is "landing among the stars".