That's kind of the point, Chrome shipped it across multiple platforms two years ago, while Safari still has no timeframe despite having a much narrower set of APIs and hardware to support. Firefox at least has the excuse of needing broad compatibility like Chrome but with a fraction of the development resources. Apple are just dragging their feet.
Chrome ships a lot of things. Even now WebGPU is marked as experimental technology on MDN.
WebGPU didn't even become a Candidate Recommendation until December 2024 (half a year ago)
> Apple are just dragging their feet.
Or they are not in any rush to implement APIs that haven't reached consensus, haven't passed reviews, are subject to change etc. Chrome has very very cavalier attitude towards shipping APIs.
Chrome has routinely shipped junk APIs with no concern for privacy, security or battery life.
It's why fingerprinting works so incredibly well on their browsers.
WebGPU is still in progress in Safari - it is available as a technology preview. The same is true for Firefox.