If you're talking about the UK, the Security Industry is suffering from a certain degree of saturation but it is mostly suffering from what I call professional inflation.
The first part fluctuates often and will likely see more demand for security in the market due to the evolving situation in Europe. It is uncertain exactly how this demand will take form as Security Officers in the UK are not allowed to carry firearms, suggesting that perhaps the demand will be more for technologies and less for personnel. But as people remain, woefully, the cheapest resource in the industry it can safely be said that you will see more vacancies for licensed security officers, despite the saturation.
The second part is the one that needs addressing - Professional Inflation. The term describes a situation where a certain class/level of worker does not possess the skills to fulfill client requests, and a more highly trained officer is hired to perform the job. Very much in the same way that a bachelor's degree is worthless nowadays, Close Protection officers are performing Door Supervisor jobs because clients with money are smart enough to realize that a 2 day course is not enough to develop the necessary skills for providing decent security, and a 15-20 day course must surely yield better results despite the fact that the content is completely different. They're just counting on the guys that successfully passed a CP course to be smart enough to adjust.
To summarize, the industry is saturated with licensed individuals but remains thirsty for truly skilled professionals.
Eldor yes I think you're right, I think it may be saturated with operators with similar experience and qualifications as you say, but the reality is that it's not saturated with quality operators. But then if the threat isn't that high do you need the highest quality of operator or can you use a cheaper option at a time when all areas of business are looking at cutting costs.
The threat is extremely high, and will become more severe in the years to come. I believe in the highest quality of operator and always tell my clients - "if you think a professional is expensive, wait until you hire an amateur..."
I think security differs from many other industries in that you can't adequately test whether or not someone can do security in an exam. You can set an exam for an electrician that test that they know all the stuff they need to do, and practical tests are relatively straightforward too.
In security there is a huge difference between knowing the theory and actually being able to put it into practice. How well do you recognise someone behaving "suspiciously", can you remain vigilant for hows on end, shift after shift with nothing happening, how well do react when something does actually happen and it is a real threat, not just an exercise?
There is a dumbing down happening in all industries and also a reduction in professionalism (people surfing the internet, playing on their phones when they should be working for example). But I don't think most have suffered in the same way as security with training companies getting grants to churn people through courses regardless of any quality or lack of.
The syllabus of SIA training is not fit for purpose and the trainers are often even poorer and I am frequently exasperated by the incorrect legal stuff people are being taught on courses (such as "we can't arrest people", "we can't use force unless we've tried to talk them down first", "if you use anything other than SIA approved PI you'll lose your licence".)
All this has meant that the industry has become packed with people of poor quality which increasingly means that the decent people are leaving.