According to Evans data, there are 26.4 million software engineers on earth, there are however 24.5 million jobs currently available with demand set to rise in the near future as software engineers are unevenly distributed across the planet. If we assume that the data above is +/- 3 million accurate its still safe to say that we don't have many software engineers on earth when you weigh our population against other professions and the world population of near 8 billion people.
One thing that organizations and HR personnel don't factor into consideration is that the developer community is rather small and because we rely on each other a lot, collaborating and sharing our challenges it's safe to say we're quite close. There are organizations that believe there aren't any good developers out there, such an accusation may hold substance depending on another factor that isn't popularly acknowledged.
A lot of good developers boycott some organizations. Usually when vacancies are shared on developer platforms we try to communicate with people who have either worked there or currently do. One memory that stood out for me was when a company offering a reasonable offer was outed by a developer who worked there, a couple devs were ready to apply till an ex-employee said "don't work for that company or you'll regret deciding to become a software engineer". After sharing his reasons which were quite valid, it's safe to say nobody applied.
Any dev who may have applied most likely doesn't belong to any community and this means that should such a person be handed a rather difficult challenge he/she has nobody to turn to for support. It's no wonder some organizations believe there aren't many good developers out there. With freelancing platforms gaining ground, developers don't have to work for a company they don't like. Organizations need to improve on company culture or they'll have to pay for it.