Lando-T's good. He's basically just the glue you need for every team. The thing is, I don't think he's worthy of a ban by himself - if he was ever removed, we would probably see very little to no change in usage stats for every other Pokemon.
>U-Turn and Intimidate for pivoting with 2 immunities
>Boosts to be a sweeper
>Stats to be a wall breaker and use choice items
>Defog / Gravity for utility
>SR / Explosion for lead
The reason he's not broken is because he can't do all of these things at once. If you broke it down by sets, while most pokemon might have a move or two swapped around, Lando-T's different sets may as well be completely different pokemon. If you broke down his usage by sets, it'd probably be 20% SR, 10% choice, 10% Z-Move, and 10% support. He's not amazing, he just fits so many roles it's hard not to chose him for a team.