I wonder to what degree the “record number of job listings” is because of the software tools that let you enter a job and post it on 20 job boards. Now it looks like 20 job openings.
As to the pickiness of employers, they are only hiring who they really need and screening diligently for skills they want among desperate job seekers and ensuring they can’t get sued in the process. So delays to hire for the few positions they have.
I think you’re right. These days, there is no way to tell how many job openings there actually are. Everyone (like HR departments) are adept at gaming the system.