Offloading image handling from our back-end web server's filesystem has many advantages. From a performance perspective, not having to rely on the bandwidth, memory, and raw disk I/O for all the image operations originating from a single web server is much more scalable. Another big advantage is that your web server's environment can be treated as disposable, because the important resources can be persisted in a separate service. This makes the complexities of deploying web applications much more straightforward, as there isn't any need to migrate content across deployment environments. Images and other large files can quickly become difficult to manage without a dedicated service of some sort.
There are many different services that allow you to upload images to the cloud. They range in terms of services, complexity, pricing...