Job Hunting

As I may have mentioned I am currently looking for a new job.
The job market is interesting and on the surface, buoyant. If you search the job boards on-line, there are thousands of advertised positions and that is just in my local area.
Dig deeper and you discover that many of them, no longer overtly, will immediately eliminate you based on the subtle way the job description is written. You can apply for all or any of them, working on the basis that by the law of averages something will strike a prospective employer somewhere!
It is of course easy to sit in your home online and apply for jobs or registering on job-sites, uploading your CV as you go. I would conservatively estimate that for every 100 applications you will perhaps garner two or three replies and one interview.
Agencies, as is their mode of operation, will also sporadically call but only if they have a positions to fill so as they can earn their commission.  
Thus far I have secured one part time job and been for one other interview which was unsuccessful. I have had a number of rejections from on-line applications, which is par for the course.
If there are so many vacancies, I ponder on where all the suitable candidates are to fulfill them? We often read and hear on the news that freshly minted University graduates cannot get employment and there are more of them than ever before. So are they all filled? What happens if they are not? Do these companies take people on and train them to do these roles? If they are all filled, whose getting them and why do so many advertised positions remain and new ones get posted everyday? It is a mystery!
I am in my sixties and therefore am not expecting many of the companies I apply to, too consider my application, in spite of the common prevailing attitude that age is not a factor! I also understand that that is not the sole reason for not being considered.
I am often told I am to "senior" with my past experience but that is just, a not so subtle, way of telling me I am too old.
Still I will persevere and continue to apply for any position I believe I am capable of doing. I am still a valid and useful member of society, with a vast amount of experience and personality, so someone with good sense will want me I am sure.