If you are on a product page then
should do the job
If you are handling the product collection in your block code, I would look into adding
for 2.3.2 and prior
I think both can be accessed via the Stock helper, but I am currently struggling with the context of this on 2.3.3 (where stockhelper no longer is a file but a bunch of migrated classes, plugins, overrides) but in your scenario it should work? And no, you don't need to fetch the children stock status, the parent is properly returned based on children.
MORE DETAILED STOCK
2.3.3 deprecated all the stockHelper ways of doing things, though they still exist. I have been trying to figure out the "correct" new way to do things and I will be honest, I am still fumbling around.
The solution currently in my "show child product stock" uses Object Manager because every time I tried the more correct approaches I get errors
But I will share the different approaches I have seen that get to the StockItem data for a product, maybe that will help you - I haven't tested these much because my current problem needs the "per warehouse" details.
$stockItem = $this->stockItemFactory->create()->load($object->getId(), 'product_id');
$this->stockRegistry = $stockRegistry;
$stockItem = $this->stockRegistry->getStockItem($productId, $product->getStore()->getWebsiteId());
$extendedAttributes = $product->getExtensionAttributes();
$stockItem = $extendedAttributes->getStockItem();