In the Bitwarden Web Vault, goes through each folder, checks if it's empty, and deletes it if so. To be pasted and executed in the browser console.

Bitwarden-Delete-Empty-Folders.js

var sleep = (ms = 1000) => {
	return new Promise((resolve) => setTimeout(resolve, ms));
};

async function deleteEmptyFolders(startIndex = 0) {
	const config = {
		sleepBetweenFolder: 250,
		sleepAfterLinkClick: 100,
		sleepAfterEditClick: 500,
		sleepAfterDeleteClick: 1200,
		sleepAfterDeleteConfirmClick: 1500,
	};

	let reCall = false;
	const folders = document.querySelectorAll(
		'.vault-filters .card-body > ul.card-ul:nth-of-type(3) li.ng-star-inserted'
	);

	if (!folders) {
		console.error(`"folders" couldn't be found`);
		return;
	}

	for (let i = startIndex; i < folders.length; i++) {
		const folder = folders[i];

		// 1. Click folder link
		const link = folder.querySelector('.d-flex > a.text-break');
		if (!link) {
			console.error(`${i}: "link" couldn't be found`);
			return;
		}
		link.click();
		await sleep(config.sleepAfterLinkClick);

		// 2. Check for "no items"
		if (!document.querySelector('.col-6 > app-vault-ciphers > .no-items')) {
			console.log(`${i}: folder has items → ignore`);
			await sleep(config.sleepBetweenFolder);
			continue;
		}

		// 3. Click folder edit button
		const editButton = folder.querySelector('a[title="Edit Folder"]');
		if (!editButton) {
			console.error(`${i}: "editButton" couldn't be found`);
			return;
		}
		editButton.click();
		await sleep(config.sleepAfterEditClick);

		// 4. Click delete button
		const deleteButton = document.querySelector('app-modal button[title="Delete"]');
		if (!deleteButton) {
			console.error(`${i}: "deleteButton" couldn't be found`);
			return;
		}
		deleteButton.click();
		await sleep(config.sleepAfterDeleteClick);

		// 5. Click confirm button
		const confirmButton = document.querySelector('.swal2-popup.swal2-modal button.swal2-confirm');
		if (!confirmButton) {
			console.error(`${i}: "confirmButton" couldn't be found`);
			return;
		}
		confirmButton.click();
		console.log(`${i}: folder deleted`);

		await sleep(config.sleepAfterDeleteConfirmClick);

		// 6. Re-call function to use updated nodeList, start at current index
		reCall = true;
		startIndex = i;
		break;
	}

	if (reCall) {
		deleteEmptyFolders(startIndex);
	} else {
		console.log('—'.repeat(41));
		console.log('            DELETION COMPLETE');
		console.log('—'.repeat(41));
	}
}

deleteEmptyFolders();