There is no set number of colleges that is considered "good" to apply to. It ultimately depends on your individual circumstances, such as your desired level of safety schools, reach schools, and target schools. Generally, it is recommended that students apply to a mix of schools with varying admission rates and selectivity levels. It is also important to apply to at least one safety school, which is a college or university that you are almost certain to be accepted to, and one reach school, which is a college or university that you may have a lower chance of being accepted to. A good starting point is to aim for around 5-8 colleges, but you may apply to more or less depending on your specific situation.
One argument against the advice that there is no set number of colleges that is considered "good" to apply to is that it can lead to students applying to too many colleges, which can be time-consuming and costly. This can be especially difficult for students who are applying to colleges that require additional application materials or fees.
Another argument is that applying to a wide range of colleges can lead to confusion and uncertainty for students, as they may not know where they are most likely to be accepted or where they would prefer to attend.
Additionally, some argue that applying to a large number of colleges can reduce the chances of being accepted to any of them, as colleges may view a student who applies to a large number of schools as less committed to attending their institution.
Finally, it could be argued that applying to a large number of colleges can dilute the quality of the student's application and make it difficult to tailor them to the specific needs of the college. In this way, the student may have a lower chance of being accepted to any of the colleges they applied to.