Bindless lets you reduce the amount of book keeping you have to do per-object on the CPU, but much more importantly opens the door for GPU driven rendering.
The problem with WebGPU is there's no bindless and the 'bindful' path is quite expensive to meet the safety requirements of a browser API. There's no way around the slow path, and the slow path is quite slow. In this case the workaround is cut features because the API simply imposes too much overhead.
But I would prefer to first bring the peformance of the slot-based binding model to a point where it is similar to D3D11 or Metal instead of ignoring that part of the API and 'skipping ahead' to bindless (which will probably have to be behind an extension anyway). Otherwise WebGPU will become a cemetery of abandondend attempts like OpenGL.