Pros
No real interview so no need to stress about one. If you can pass a drug test you're hired immediately. Not much need to think - you need to pay attention the whole time but once you get the hang of it you can kind of daydream throughout your shift. It's physical, so working a full shift feels like a workout and I slept great after work. Clock in/clock out - not a job you take home with you or worry about off the clock. You start ASAP and get full benefits day one - that was my main reason for working there.
Cons
You are basically a human robot/cog in the machine, so you need to accept that. Turnover is very high and the work is physically demanding - if you're lazy or call out frequently, you will lose your job. Very little social life - most are just clocking in for their shift to do a job, not looking for friends. The picker position in particular you work at a station on your own, so you won't be chatting with anyone while you work. It's silent and repetitive, but you have to pay attention the entire time, so both your brain and body are tired at the end of a shift. I am strong for my size and very physically active, but I developed carpal tunnel almost immediately due to the repetitive movements of my hands and wrists. I started right before Black Friday and went from zero to 12 hour shifts of the same movements 40+ hrs a week. Even though you are hired immediately, you get no say in which department you are placed. You can't choose a department, and if you eventually want to switch from being a picker to another department, so do most pickers, so seniority and reliability matter.