magento2.4.0 – Persist Product setData

I’m using the following code to try and update a product’s description:

$product = $this->productRepository->getById(5);
$product->setData('description', 'foo');
$this->productRepository->save($product, $saveOptions = false);

While the data does get saved
(I can fetch it correctly via $product->getData('description');),
it is not changed in the db and thus no changes in the actual description.
Are additional steps necessary or am I using a false approach entirely?