You are confusing designing with distributing.
Facer is not a design tool. Unless you stick with the default components and play Lego.
Any original watch face is made of graphic elements created with specific tools like Photoshop and/or Cad software. These elements are then assembled (and interactivity may be added), either by creating a standalone app with a compiler software (like Android Studio) or by means of platforms like Samsung Gear Watch Designer, Watchmaker or Facer.
Once you've done assembling, you can distribute the watch face on the Play Store, Galaxy Store or Facer, depending on the tool you've used. With the further, not negligible difference that, while with Android Studio you create, distribute and own a .apk file, with Gear Watch Designer a .tpk file and with Watchmaker a .watch file, nothing of the sort happens with Facer (why am I not surprised?).
I sell many watch faces designs on the Play Store and on the Galaxy Store. Yet, curiously, neither Google nor Samsung asks for an exclusive distribution agreement.
They must have a very high unprofessionalism tolerance threshold.
Some of my watch faces, featuring the same design, have different characteristics depending on the specificity of the platform. Consequently, they have different prices. My Wear OS watch faces, for example, have more features, since I can truly access and program the watch hardware, hence they are a little more pricey.
More features imply higher prices.
Less features, lower prices. And if you force me to put a zero price tag on my watch face on your distribution platform, than you get zero features. In other words, a demo version.
It's plain simple. It's my design. I decide what I give away for free.