This is a feature request on the behalf of all web developers targeting mobile. Here are reasons the toggle switch element should be natively available in HTML forms:

• Switch is a standard and popular UI control in both Android and iOS mobile platforms.
• Checkbox is used in websites due to the absence of the switch. Checkbox is absent from iOS and is not considered a good part of the human interface for forms on mobile. Checkbox has a smaller hit area than switches.
• Switch is very popular in UI frameworks that have been providing this as a component to use - Material Design, Bootstrap, React Native
• Switches are non-trivial to implement properly in CSS. See Codepen, W3Schools. Most frameworks that are provided to generate HTML on the server do not have a switch causing developers, especially enterprise using checkbox in the place of a switch. PWAs without switches appear non-native on mobile platforms.
• Implementing switches should have no performance overhead for the browsers (separate component in the UI).

I am happy to help writing a spec for the <input type="switch" /> element if that can help getting it into the browsers.