Services like legal, medical, banking, charted accountant, financial analysts, real estate, insurance etc. are some examples. Whenever such services flourish it generally leads to dysfunctional society on its way to collapse. Let's go through some of these examples.
Legal Service
Even though laws are made to address a minority of problems in the society, over a period of time laws are passed either by legal departments or politicians which generally make people irresponsible. Please read the blog post "Laws make People Irresponsible" to go farther on this topic. Lawyers and judges create precedents, so that the legal service gets more revenue for their own benefit, which in turn encourages more professionals to get into this service. The more cases, the larger set of people in conflict with each other because of trust issues, failure to adhere to prior obligations, being prone to cheat, etc. Over a period of time people behave and hide behind the legality of the problems instead of solving themselves. Eventually more professionals in this service create more laws, to address ever tinier problems which in turn creates more conflicts. This leads to an ever greater number of cases and the legal system thinks they are the moral saviours of the society.
Medical Service
Medicine is another service which is useful to solve health problems. When people have bad health habits, and are pushed by food industry through media to eat poorly made food without concern for nutritional content or portion limits, generally people have severe chronic diseases like diabetes, cancer, arthritis, etc. Over a period of time doctors, hospitals, clinics, diagnostic centers flourish and eventually they form a business instead of a service. Doctors/hospitals now act to increase their profits rather than letting people know the true source of their ill-health, and genuinely solve their problems. The majority of general practitioners are pretty useless for good health. However, now people tend to visit doctors for each and every small problem instead of healing themselves, with age old remedies available by natural healing, and doctors are happy to have them. In a way, the increase in medical industry means an unhealthy population in that region.
Charted Accountants (CA)
It is theft to steal one's hard earned money through taxation, however, we are forced to do so. Normally these laws are simple and people in that region easily follow such rules. However, over time taxes get more complicated and that's when CA services flourish. This leads to more middle men, and people over time fail to learn the system to stay on top, and end up relying on these services. These men then charge hefty fees in a now self-perpetuating system. Instead of removing tax laws more and more are created to enslave humanity under the name of providing services. By this mechanism normal people lose understanding of these laws and eventually they must hire these professionals.
Brokerage/Real Estate Agents
Generally when a property is being traded there is buyer and a seller. There is no need of another third party to register the sale legally. However, the rise of agents happens when the sale is large and complicated. As years pass by, there arises a percentage based commission taken by the agents to seal the deal. Slowly, more unproductive agents, lacking any other skills, get into this business and they themselves start trading property without any development of that property, thus driving up real estate prices. This creates artificial inflation and farmers or other people who really want to produce cannot afford the land. Also more complicated financial instruments are created and sold to customers. Over a period of time people participate to chase a rising market for short term gains. Eventually this leads to a huge collapse which can affect a large set of the population.
Problem: Upon pondering one notices that all these services are non-productive third party services, meaning they do not produce goods when compared to farming, agriculture, engineering, etc. The fact that such services are thriving means society is dysfunctional, because of complicated laws, people being careless of their health, and people stop fighting the system and get used to the comfort.
Solution: One cannot absolutely avoid the service sector as they do serve some purpose. However, people need to actively avoid such services as much as possible and need to learn for themselves. This implies laws/ and rules should be simple enough for normal citizen to understand and implement themselves instead of requiring professionals. Another solution is to abolish counterproductive rules. One also needs to stand up against the government to stop unfair and overly complicated laws/rules/acts being passed in the future. Comfort leads to misery, so do not think it's not your job to help create the system or hope a different party will solve your problems. Be cautious, and actively participate in the process for the betterment of your society.