Massive overhiring or not, it's the fact that many (skilled) engineers can't find a job. Many companies were shut off during the past few years and market became oversaturated over the night. Whether AI will help to correct the market creating more demand we will see but I wouldn't hold my breath. Many domain specific skills became a commodity.
We had a huge boom due to the low interest rates allowing businesses to pay developers with borrowed money, effectively operating at a loss for years on the basis of future growth. Now interest rates have risen the need to actually be profitable has caused a lot of optimization and lower hiring overall.
Where's the fact coming from, as in it's higher than before? I seem to be getting more than ever recruiting emails, and have felt out interviewing at a few places which we're very eager to find staff level talent.
Personal experience and also from many people I know around. Previously I would receive a request for an interview every two days or so. Lately, perhaps once a month, if at all. Foundational skills that I have were always scarce on the market so that makes me believe that the demand for them is now much much lower.
Another data point is that there's been ~10 companies that I have been following and all of them have been shut down in the past year or so.
And the general feeling you get from the number of HN posts from people complaining about not being able to find jobs. This certainly hasn't been like that before.