JSFiddle - React, Tailwind, and code Playground

HTML

Some text and code
<span id="sc_start_commenttext-330"></span>I shall disappear!<span id="sc_end_commenttext-330"></span>
Some Text and code

JavaScript

var $spans = document.getElementsByTagName("span");
    var str = "";
    
    for(var i = 0, $span, $sibling; i < $spans.length; ++i) {
        $span = $spans[i];
        if(/^sc_start_commenttext/i.test($span.id)) {
            while($sibling = $span.nextSibling) {
                if(/^sc_end_commenttext/i.test($sibling.id)) {
                    break;
                }
                str += $sibling.data;
                $span.parentNode.removeChild($sibling);
            }
            
        }
    }
    
    console.log(str);