I've never even worked at a place that does promotions. Sure if your boss leaves you can apply for their job but it'll be offered to externals as well and then you'll be compared to them as an external applicant, i.e. with resume + interview. Job performance doesn't matter, HR makes no effort to even measure performance beyond PIPing people who don't show up.
Weirdly when I mention this to colleagues, who know for a fact that's how things work here, they're surprised because they never noticed. Like everyone has a mental model of 'good workers get promoted' which is seemingly impervious to direct experience.