In the comparison above, you can see the visual difference between a web-based custom-created experience (left) vs a Spatial.io scene containing the same.
The web3D version has 100% freedom to create what we want, including static or video/animated walls, which is not possible on Spatial.io
Spatial.io makes it easy to incorporate 3D Avatars and has all the communication tools at hand when you are inside the experience. Those elements are possible to incorporate into the web3D experience but need to be defined and added.