When is Firebase justified?

Question

Android

In one of the applications, it is necessary to implement the delivery of notifications from the server to the client. The server contains certain logic + database (I'm not just saying). While studying this topic, I learned that GCM is ... "legacy.. kind of.. feature" and that it is recommended to use some kind of Firebase instead, but when I started to understand it, I realized that it contains far more than just a feature delivery of notifications to the client, but also a bunch of other unnecessary (for me in this application) functionality such as the built-in database and God knows what else. Actually, in connection with this, I had (as it seems to me) quite an adequate question - is it necessary at all?
Facts in favor of its use:
+ Google recommendations that clearly say "If you are integrating messaging in a new app,
+ Perhaps faster message delivery? This factor is decisive, but I did not find any information regarding speed
+ Just more recent technology
Facts that indicate the need to abandon FCM:
- More to study in connection with all this functionality (but I have not used either FCM or GCM before)
- More weight applications (not critical)
- Extra functionality
- Maybe something else will appear
- Less information (simply because the technology appeared later)

Answer 1

FCM == GCM
Just made it part of the firebase. They also put ads in there and probably something else.
If you do not need anything else from firebase (real time database, storage, etc.), do not include libraries in the project and that's it. It is possible to connect exclusively FCM.

Answer 2

You forgot to mention in the cons of Firebase that it is not free (with a certain amount of traffic). If the budget is not critical - use it, in the future you can make a bunch of cool things based on it. At the expense of extra functionality - why is it a minus? Just don't use it. On the contrary, this "extra" functionality can be used in the future, say, when introducing new features.
But, if you only need message delivery, and you are 100% sure that more functionality is not required, use GCM. It is easy to implement and does its job well.

Answer 3

Use FCM, there won't be any difference for your server. API for sending messages remains the same