why?

High school never ends. There are beautiful girls in every house and smart girls in every house and funny girls in every house - nothing really makes a house better other than its overall image - aka the average girl in the sorority meets a certain standard - but even those are constantly changing. The point of rushing is to find girls help you step out and be social - whether or not you're top tier mid tier bottom tier doesn't really matter except to those people who are shallow and are still living in a high school mindset. Good job for being one of the ones that isn't. Rush if you want, it has its cons but it also has a lot of pros

Real talk here. Tiers are just people being shallow as a kiddie pool and are mostly based on looks. (Even though it should be based on the Greek Life values of scholarship, leadership, service, and friendship in my opinion.) Tiers only really matter during recruitment when chapters start putting others down in the hopes theirs will do better and when people are planning mixers. It really is like you're back in high school. Other than that, they don't matter. Most girls are friends with people in other sororities, they experience the same Greek traditions, and most frat guys don't care as long as you're cute.
So if you want to go through recruitment next year (and I hope you do) it'll benefit you to stay off here and focus on getting to know REAL Greek women. Good luck to you!