If you only need one reason to adopt a cloud phone system, it's that it will save your company money while providing no loss in terms of quality of service. There, the most important thing about cloud phone systems has been explained. Nothing else need be said for many organizations. When a piece of technology comes around that does exactly what the old one does, but for cheaper, it invariably become dominant in the market and crushes the previous industry standard. But there are factors beyond cost that are useful to examine for anyone who wants to learn more about cloud phone systems.
Beyond cost, there is, as Maurice Nagel puts it, "simplicity of operations." When a phone system is hosted off-site but available from anywhere, it makes it very easy to connect to and utilize all of the features of a given phone system. This is useful in just about any organization because it allows employees to sync up their mobile phones with the servers used to power the company, so that workers can take calls on their work number just as easily as their personal phone number. By making use of this ability, it can be possible to instantly make mobile work available to all employees within a company. Workers that can stay in touch have no reason not to just head out of the office for coffee whenever they want - they will always be able to reach each other. Anyone with a home computer and a functioning piece of equipment there could potentially access their cloud phone system account from home and take office calls there if they needed to telecommute.
Better for less
Even if a cloud phone system didn't provide the above advantage of mobility, it would be worth it for many organizations to adopt the new technology. Even then, there are more uses. Hosted systems take much of the complexity of running a phone network off of the hands of a business while retaining the customizability it would have if it ran its own service. This means that a group can get the same kinds of forwarding system and similar that they would normally get through their own system, but now without the hassle of having to figure out much of the technical work on their end. When organizations that exist to run communication do you grunt work for you, you would be surprised by how much easier it can be to utilize their services.