Kuzzle has no hosted version. In order to use it, you have to install it to a remote machine. This can be cost-effective but it also adds overhead because you will have to take care of the hosting and backend infrastructure yourself.
In order to use kinto you have to download it and host it on your own server infrastructure. While it does help you avoid outsourcing your data to a third-party, it also adds the overhead of having to maintain a backend for your app.