Vantaggi
Endless opportunities, even without a college degree. I've seen a LOT of people move up from tier 1 to operations manager/senior management and beyond in as little as 3-5 years - many of whom don't even have a college degree. Even if you're not quite looking to move up to senior management, you can still move up or find a more suitable job role just as I did. Operations wasn't for me, so I studied briefly and applied for an IT support role and got it! There are so many different departments and job roles at Amazon and you can move around as much as you want until you find the right fit. I can't speak for other department, but in IT, Amazon will cover the cost of every certification you may want to get to advance your career. They even have programs like the "Amazon Technical Academy", in which a tier 1 (or any blue badge/Amazon employee) can get into Software Engineering.
Svantaggi
You probably won't be working M-F if you're in any Fulfillment Center. Not necessarily a "con", but it'd be nice if Amazon subsidized education up to a Bachelor's Degree. They currently only pay for up to a two-year degree or equivalent (and have many other programs that aren't so long, like getting a CDL).