The area you're working in may be very drab and depressing. No windows, blah paint, ugly lighting. You do get to personalize your cubicle a bit.
Like most call centers, you have metrics to meet and it's hard to be in control of all those factors with calls varying based on customers. You could be the lucky duck that gets 10 tough, time-consuming customers in a row.
No phones, no pens, no paper for security reasons. If you get a slow day, sucks to be you. Can't even doodle or do homework. At least you can have rubix cubes, fidget spinners, and other toys.
You have to ask for bathroom breaks. No fun for those with IBS, heavy periods, etc. Also makes you feel like a 4th grader needing a hall pass.
Most of the people you love will quit. Turnover is high. Not everyone is call center material. I certainly was not. Training is pretty boring, even with the funniest teachers.
Kronos sucks! Punctuality is paramount and tough to achieve with the computer systems loading slowly. You can only clock in 5 minutes early, so getting there super early to avoid lateness is pointless. The same goes for lunches. If an old lady walks out in front of you on the street, management talking in the halls, or if there's some other issue beyond your control that makes you a hair late, you get dinged. If you mess up your time card, it's highly frowned upon ... more so than any other workplace I've been in ... and sometimes, it's the computer's fault it's messed up.
Like with most jobs, certain supervisors are not pleasant. There are some icky politics there. Part of the reason I quit was because a coworker we all liked was driven to tears, and quit after being falsely accused of a crime without solid evidence. One of the accusers was very unprofessional. Can't say for sure, but he may have even framed the accused. Either way, he had a habit of bad-mouthing other employees. The person he accused never did so, and always treated him with respect.