Very few firms want to hire juniors, while nearly all firms desire senior-level talent. This manifests inflated job vacancies because so many firms have an evergreen job posting for "Senior Full Stack". Because talent is scarce these roles rarely get filled (hiring managers expect million-dollar candidates to accept $100-200k compensation). Also, because lots of software requires specific expertise, there are vacanci…
It's not that they don't want to hire juniors, it's that you need a solid ratio of mentors to mentees.
I've worked at a LOT of companies, and for the more well known one, the ratio of junior resumes to seniors was easily 1000:1.
We hired entire cohorts of juniors, often interviewing HUNDREDS of them in a couple of weeks, hiring dozens. That still meant that from all the resumes we got, only a few % made it through.
What choice did we have though? We can only train mentors so fast, and hiring them is hard and expensive. You can't ask someone with 5 years of experience to train 30 people at the same time.
People often underestimate just how many people are entering the field right now, vs how many were 10-20 years ago. Add in people who EXIT the field, as well as people who are poor fits to be mentors, and it gets really dicey.