I started using Firebase over 5 years ago because of the 'real-time' nature. I originally used to use Real Time Database, but now I use Cloud Firestore. I recommend using the Google Firebase PaaS to quickly develop or prototype small to enterprise level web/mobile applications. Since Google purchased Firebase, it has exploded and it growing rapidly. I also find some level of comfort that it is Backed by Google.
Firebase is a great way to work on an MVP very quickly with the ability to work on all your backend functionalities using the #firebase function to connect to features like the Realtime database, Firestore to Firebase notifications and Firebase ML Kit. If you want to work on a new product and get an MVP out immediately or soon, use firebase has your cloud service of choice or AWS if you don't mind cost