They were invented so that more young people in Hong Kong can participate in post-secondary education - without having to create more university places, and without the government having to spend a lot of money, because much of the associate degree places receive little or no funding support from the government.
So, are they good value for the money?
Some associate degree programs are offered by community colleges associated with universities. These are the best ones, because they can draw upon tangible and intangible resources available in the universities such as the experiences of the staff, curricula, procedures, connections, etc. Many of their staff used to work in universities, on higher diploma and even degree programs. Stepping down from degree to associate degree, or sideways from higher diploma to associate degree is relatively easy.
Some are offered by organizations that used to offer diplomas, certificates, or the like. for them, it is a step up in the academic ladder and it is not easy. They are not getting a lot of help either. Most of these programs struggle and some have already shut down.
Some are offered in association with overseas institutions. These can be of varying quality and in general they are not as good as those with strong associations with local universities. Many people in Hong Kong tend to be impressed by overseas universities, particularly those with familiar sounding names. But the quality of education in Hong Kong has improved tremendously in the past 15 years. So much so that we are now exceeded only by the very top tier universities overseas.
What is more important is that overseas institutions offer programs in Hong Kong for financial gain, not because of altruistic motives. Often their contribution is not much more than the name, and the basic course material. The delivery is mostly by locally-hired staff, who are not paid that well, to ensure healthy returns to the overseas institution. So the local hires do most of the work, while the profits revert to the overseas institution.
When they enter the universities (and these are the fortunate ones), even the top graduates from the best associate degree programs struggle to keep up. Those who thrive are the exception, not the norm.