iOS speech recognition: webkitSpeechRecognition in a WKWebview vs. native SFSpeechRecognizer

I have a prototype web view (in a WKWebView) that uses webkitSpeechRecognition for getting short snippets of text from speech. I'm not thrilled with the quality of the "recognition" - the text generally isn't very accurate.

I'm wondering if I'll get any more accuracy by using the "native" SFSpeechRecognizer. It seems to me that webkitSpeechRecognition is likely just a Javascript wrapper interface for SFSpeechRecognizer, and the quality of the speech recognition won't improve.

Does anyone know for sure if this is the case? Does webKitSpeechRecognition on iOS use SFSpeechRecognizer under the hood? Or are they two completely different recognition systems, and one could be more accurate than the other?