Kobo is already by far the best e-reader brand and things like this just cement it further.
It is the only mainstream e-reader I'm aware of where you can simply change a single line of configuration and make it sync with your own server instead of Kobo's while keeping all of the stock software exactly the same. There are even server implementations that proxy to Kobo's server if you want to sync some books from your own server and some from Kobo's.
Other options either make it impossible to sync from your own server or require you to install different apps like KOReader, which though powerful is a really janky experience compared to the stock app (and of course you can use KOReader on Kobo if you want to).