The companies that are abandoning junior roles are making a life-or-death bet that AI will eventually replace ALL work. Because those senior people will NOT be around forever. And they have killed their talent development and knowledge transfer pipelines. Either direction you take it, this feels like a lose-lose situation for everyone.
People don't think in terms of shared commons and that if all companies are doing the same thing then there won't be much of a "senior" market left to hire.