What are some alternatives?
When comparing Vectary and Sketchfab, you can also consider the following products
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Cinema 4D - Cinema 4D is a 3D modeling, animation, motion graphics and rendering application.
Autodesk 3DS Max - 3ds Max is software for 3D modeling, animation, rendering, and visualization. Create stunning game enrivonments, design visualizations, and virtual reality experiences.
Sculptris - Sculptris: Enter a world of digital art without barriers.
Wings 3D - Wings 3D is a subdivision modeler inspired by Nendo and Mirai from Izware.
ZBrush - ZBrush is a digital sculpting and painting software solution.