The contract might look good on paper - personally I don't think it looks that good anymore - but the reality is it's all the small details that ruin this job. Six months+ of mindless training getting treated like a 200 hour cadet. Check to line and still treated like a 200 hour cadet. Admin staff that won't help you out even if it's in their best interests as well. Filling out a 5 page google form for every stupid thing (seriously, you'll lose at least a couple of hours of your life every single month). Bussing back and forth and back and forth between Narita and Haneda hotels, which doesn't count as duty and is almost always rostered before or after a flight. Knowing that at any time you could lose your shot at an upgrade, just because you did something trivial to upset them. You can't raise even the most simple problem without being treated like crap for the next six months. I could go on...
And this is before you realize that the contract isn't worth the paper it's printed on. This was learnt the hard way when the pandemic rolled around.