Behold my jQuery replacement:

    export function each(qs, cb) {
      if (typeof qs === "string") {
        qs = document.querySelectorAll(qs);
      }
      if (!qs) {
        return;
      }
      if (qs.length === undefined) {
        qs = [qs];
      }
      for (var i = 0; i < qs.length; i++) {
        cb(qs[i], i);
      }
    }

    export function on(ev, qs, cb) {
      let cancelFns = [];

      each(qs, (el) => {
        el.addEventListener(ev, cb);
        cancelFns.push(() => {
          el.removeEventListener(ev, cb);
        });
      });
      return () => {
        cancelFns.forEach((fn) => {
          fn();
        });
      };
    }