It's been about 9 months since I stopped developing in parallel on both hoodie and firebase and decided to stick with firebase. So my information may be a little old. But here's some comparison off the top of my head.
One main requirement of our group was simple hosting, and firebase hosting seemed to fit the bill. There seems to be no viable commercial service providing turnkey hoodie hosting the way firebase does. It turns out that in most cases you'll still need to run your own server with firebase, to do things like email verification/password reset, collecting payments, or managing queue sizes, but it's still nice that they do most of the heavy lifting of the database server itself.
Firebase documentation and support is so much better--- it's much much easier to get started.
Hoodie has an advantage that it is offline first. Firebase claims offline support but it is limited to their iOS and Android clients, and even then, it is not complete: local storage of transactions is not supported. Most of the effort developing my own app on firebase (web/react and react-native for iOS) went into building my own local storage and handling synchronization with firebase.
Hoodie on the other hand uses a very different synchronization model: it basically implements a local couchdb and uses replication to sync to the couchdb server. I needed transactions for my app and I think it would have been very hard to implement with hoodie.
Since in hoodie the local db is (or was anyway) implemented on local storage, I found it intolerably slow for a reasonable amount of data. It took an unacceptably long time to start up as it read the entire contents of storage into a cache.
Then there's the user base. Firebase claims a huge number of developers and even though the vast majority of them probably are not shipping, the hoodie user/developer base is very small and progress is slow. Have they finished their extremely important project of rebasing their local db on Pouchdb? I wouldn't consider it if that's not there.
Although I was strongly biased towards hoodie at the beginning of my journey, in large part because it is open source, practical considerations favor firebase hands down.
Hope this helps.