1) There's always something to learn from everyone.
You might be a great musician, songwriter, or arranger, but being in a cappella teaches you how much more there is to learn. Your range will increase. You'll pick up vocal percussion. You'll learn to network for gigs. Or if you're feeling adventurous, you'll start to sing a whole new style of music altogether.
2) You always have to be in harmony with one another. Literally.
If the group doesn't strike a good chord together (in both senses), chances are the group will fall apart and disperse. Sometimes someone might be off key or never have been trained for the situation, but it's the job of the senior members to help get the said member on board and in tune. But most importantly, the bonds have to be genuine, or the group isn't going to go anywhere. The "fake it 'til you make it" route is not enough.
3) Everyone holds a piece of the group reputation in their hands.
Your grades and record are all fundamental to the group. It doesn't matter how skilled or hardworking you are. If you have bad grades or a spotty record, you're not getting accepted, or might be kicked from your current group. A cappella prides itself in being full of academically smart and musically apt people. And if one person were to get kicked, it would hurt the group. Take any of the guys below and remove them. It would create a loss of balance, in sound and in aesthetic alike.
4) Work hard, play hard.
We learn the songs to the best of our ability, and make sure we develop strong and powerful voices. But after time's up, we just relax. We get food, hang out somewhere, play an escape room, go to a party, anything to let off the steam.
5) Auditions and Callbacks are hell.
From bids and auditions to pledges and callbacks, it's all the same. You're the same dancing monkey, but you're singing rather than doing weird trials. There's an intimidating look that all of the current members give you. When they pick a few auditionees to sing in small groups, it gets really scary, especially when they walk around and listen to you individually. Every now and then, they'll ask you to solo, which is also terrifying.
6) You join an awesome community.
A cappella is a quickly growing and well-respected community (thanks, Pentatonix!). Greek Life exploded in the 20th century, and in the 21st century, it's a cappella. We might be just as cultish as Greek Life is, but a bit more inclusive.
7) Singing is a side hustle.
You can actually make great money on gigs. The person asking you to sing will often pay you. To get any extra, just set a bucket or box out in front, and you'll make a little extra. That money goes back into the group to fund later concerts, getting sound equipment, and maybe even get recording space.
8) You learn to love each other no matter what.
A Cappella is born out of a lot of hard work and working with your group no matter what happens. What you'll get out of Greek Life is just a fraction of what you might find A Cappella Community. So if you're into music in any sense, why rush, when you can "aca-rush"?