Something that works now and will continue to work for years without changing any code.
To turn this on its head, if I'm creating a new product now, why invest time into an API where by the time the product would be ready with WebGL, instead I chose WebGPU, so now have the risks:
- The API is still years away from mainstream.
- Doesn't solve anything for my use case that wouldn't be solved with WebGL.
- Is too buggy to use on most configurations.
- Isn't supported by X hardware or Y OS.
- Has security issues that make browsers disable it for years.
- The code has to be regularly updated/maintained/fixed when browsers update.
- Performance could be lower for low end systems.
- Even if everything worked, it's a lot more work to do everything (e.g. VULKAN).
- To beat webGL, you have to optimise specifically for mobile/desktop/amd/nvidia/etc
- The documentation is poor.
- It's impossible to hire an expert in webGPU.
- It's very expensive to test every combination of GPU/OS/driver so you have no confidence it is working correctly.