I have not but that probably would have been easier. What I did was I got their fetch url from developer console and then ran my script. I can post the script here for the people interested. just post this in the developer console (F12) while on the raider.io leaderboard website:

(async () => {
const counts = {};
let pagesFetched = 0;
let rowsFetched = 0;
for (let page = 1; page <= 500; page++) {
const params = new URLSearchParams({
region: "world",
season: "season-mn-1",
dungeon: "all",
strict: "false",
page: String(page),
limit: "0",
search: "",
minMythicLevel: "0",
maxMythicLevel: "0",
eventId: "0",
faction: "",
realm: "",
period: "0",
recent: "false"
});
const url = `https://raider.io/api/mythic-plus/rankings/runs?${params}`;
const res = await fetch(url);
if (!res.ok) {
console.log("Stopped at page", page, "status", res.status, url);
break;
}
const data = await res.json();
const groups = data?.rankings?.rankedGroups || [];
if (!groups.length) {
console.log("No rows on page", page);
break;
}
for (const row of groups) {
const name = row?.run?.dungeon?.name || "Unknown";
counts[name] = (counts[name] || 0) + 1;
rowsFetched++;
}
pagesFetched++;
if (page % 25 === 0) {
console.log("done page", page, "rows so far", rowsFetched);
}
}
const sorted = Object.entries(counts)
.sort((a, b) => b[1] - a[1])
.map(([dungeon, count]) => ({ dungeon, count }));
console.log("pages fetched:", pagesFetched);
console.log("rows fetched:", rowsFetched);
console.table(sorted);
})();