Colleges or universities are considered to be the highest level of education system. People who did not attend a college or university usually envy those students (어떤 student들?). There would be several reasons why people hope to enter college or university. From my perspective, I think (이미 my perspective라고 하셨기 때문에 생략하셔도 됩니다)there are two main reasons for entering college or university: to learn deeply about what they are curious about, and to prepare for their career path.
First and foremost, people enter colleges or universities in order to study their fields more specifically. Most people desire to learn something that is interesting to them. Curiosity is one of the most fundamental aspirations for human beings. Some people would be interested in math, others would hope to learn chemistry. (불필요한 내용) Colleges or and universities give people a chance to [think about their major] (*), discuss with others, and study deeper than before they were in when they were high school students. From colleges or universities, people can learn what they did not understand before, enhance their knowledge, and find out new phenomenons phenomena (phenomenon의 복수형) or inventions by researching their own fields.
*: 전공에 대한 생각을 할 수 있게 해주기 때문에 대학을 가는것인지 아니면 대학을 가기 때문에 전공에 대해 생각을 하게 되는 것인지 물어 보고 싶네요.
Second, people try to prepare for getting to get a job by studying from at colleges or universities. Although many people like their study in one way, they also are stressed by the study in other way. This is because they have to get a good grade in order to prepare for their future job. Education of [college or university education is one of the basic requirements for getting a good job because companies want to hire highly qualified people and they think college or university education is an appropriate method.] (문장이 너무 길어서 읽기가 힘든 경우가 생깁니다) People who want to enter a top class college or university usually think that one of the many good ways for getting a good or high salary job is to graduate from a top class [school] (일반적인 표현들을 구체적으로 바꿔 쓰세요. school이라 하면은 초/중/고/대 다 해당이 됩니다). Their purpose of entering a college or university is mostly to get getting a good job.
Several other reasons would be possibly come up for different people. Although other various kinds of reasons are [sensible] (sensible이라는 단어의 뉘앙스가 사람을 대상으로 하는 말입니다, reasonable/rational 이 더 적절하다고 생각됩니다), I think the most common reasons for entering colleges or universities can be classified as [these mentioned reasons] (이렇게 표현하시는 것 보다는 다시 한번 위의 내용을 요약 해서 쓰시는 것을 추천 해드립니다.).