Most of those updates only apply to the latest. So it isn't just Android it is all the other parts too. For a few months you can only get security, but eventually they decide the only version they support is the one with whatever changed google made to the core not related to security as well.
It's a huge advocate of keeping all my data private but now knowing how useful it is to anonymize, encrypt and use it all on my device with things like Google Pay, I strongly advocate if you're using Google or Samsung services to update.
Plus these updates usually are Android level and not related to Samsung or Google