Funny, so far Legion and BfA have kept me playing longer than any other expansion where I used to take breaks for one or even two raid tiers.
I mean everyone has different reasons for playing and all that but really the biggest criticism of BfA - the AP grind and need to regrind to get your traits again - haven't been an issue for about 6 months now.
Some classes aren't in great places but others are in good spots of accessibility versus min/Max and frankly that's the case with every expansion so I don't worry about that ever.