> Shoelace forms don't make use of action and method attributes and they don't submit the same was as native forms. To handle submission, you need to listen for the slSubmit event as shown in the example below and make an XHR request with the resulting form data.
However, that's only currently shipping in Chrome, despite the other browsers being positive on it.
Similar capability gaps that we're working to close are accessibility (https://html.spec.whatwg.org/multipage/custom-elements.html#..., same situation, everyone likes it, only Chrome ships so far) and focusability (https://github.com/w3c/webcomponents/issues/762, still figuring out what the solution should be).
Shoelace author here. This is somewhat true (I wouldn’t call it “a bunch” though), and it will be until form-associated custom elements are standard. However, I’d argue that most form validation and submission is done with JavaScript these days. I can’t think of the last time I saw a post request submitted from a form in the wild. (Not that it doesn’t happen, but it seems to be quite rare now.)