Honestly I think the diamond-ring culture is deeply unhealthy - it creates an artificial large resentment event right at the beginning of a commitment, that may destabilize the whole relationship.
I've seen threads on r/relationship_advice and r/TwoXChromosomes where women are desperately distraught over issues having to do with the ring their fiancé/husband bought them, it really does seem like unnecessary hardship.
Though, as a man, figuring out your partner's expectations of rings and weddings (and family and children and ...) is part of the dating process. You really shouldn't be blindsided at the engagement phase.
I'm reminded of a friend from high school who is got divorced after finding out his wife of two years didn't want and never wanted children. His defense was "it just never came up!"