There are a host of problems that could go wrong with projects (and, in my experience, the largest problem being a lack of communication.)
THIS - the lack of communication - is the biggest problem Agile solves. No, you don't have to use Agile to solve the communication problem, but I wager the solution you come up with will look a lot like Agile. And yes, Agile is no panacea and has its own downsides, but solving the communication problem is such a tremendous benefit that the downsides are often marginal.
If you don't have a communication problem or a communication problem isn't the biggest obstacle to your successful delivery then perhaps Agile may offer little benefit or take you on a tangent introducing other problems while not solving your main problem. The worst thing you can do is adopt processes because everyone else is doing it.
THIS - the lack of communication - is the biggest problem Agile solves. No, you don't have to use Agile to solve the communication problem, but I wager the solution you come up with will look a lot like Agile. And yes, Agile is no panacea and has its own downsides, but solving the communication problem is such a tremendous benefit that the downsides are often marginal.
If you don't have a communication problem or a communication problem isn't the biggest obstacle to your successful delivery then perhaps Agile may offer little benefit or take you on a tangent introducing other problems while not solving your main problem. The worst thing you can do is adopt processes because everyone else is doing it.