Lightroom Mobile is used on mobile devices e.g. on iOS.
I use it to sync different collections from my Lightroom on my mac to my iPad and iPhone. These collections are also visible on the web on ligthroom.adobe.com with your Adobe ID.
If this is better than google photos, I don't know. I am really happy with Lightroom together with LR mobile and lightroom.adobe com.
I am not sure, if this answers your question. If not, tell us what you want to do with LR mobile, and what you expect from LR mobile
Daniel (from Switzerland)