Why is there no way to identify the quality of photographic works (especially portrait photography) and the level of photographers?

From the standpoint of a photographer, I think the definition of a good work is:

The charm of images lies in retaining the moments of beauty and arousing people's wide recognition of beauty. The same is true of art, which can arouse people's singing. The so-called "a thousand people have a thousand Hamlets in their hearts."

If you have time, look at the photographer's previous works, which can impress people and last forever. Beauty is not the whole of photography. A good video work brings you a memory, both at that time and in the years to come. Good works are works that can move you when you see those images.

From the customer's point of view, theoretical things are not practical, pleasing to the eye, and attracting talents is a good work.

In short, you should not take pictures of people you don't know. Truth is the best, not superficial use of light, composition, clothing modeling and so on.

The first photo is nice, and the second is that Zhang Cai is the real you.