Were there ever that many low-level Junior jobs though?
In my experience, almost everyone in college would get an internship Junior / Senior year and convert into an FTE after graduation. Those that were not so talented or not so lucky usually struggled to find work, taking many months to finally land a job. Most typically at a Booz Allen Hamilton type of place that was just throwing bodies into seats.
At all of my employers, I’ve never really seen any openings for Juniors, only Mid and Senior positions. The few Juniors we did bring on outside of an internship pipeline were either internal transfers, e.g. a SOC analyst given a chance or a nepotism type of hire.