Could you please share a screenshot so that I investigate what actually happens? I tested on a few different devices, but far from anything extensive.
Can you try if increasing "render scale" in params->display helps?
The rest of the circular aliasing could likely be fixed by requesting MSAA, so e.g.:
renderer = new THREE.WebGLRenderer({ alpha: true, antialias: true, powerPreference: 'high-performance', })