Yeah, they seriously missed great opportunities. The episodes I liked the best (in an overall bad series) were the ones that explored these histories. I enjoyed the Vulcan episodes that revealed an intolerant and autocratic government.Yes my favorite parts were when they filled in backstories that enriched the existing Trek lore. They fleshed out the Andorians and Vulcans quite a bit. Even the Tholians and Tellarites made their appearances. In a prequel series there is so much opportunity to explore existing races, their history, their culture, and their relationships.
But instead we got stories with Suliban, a generic race that comes out of nowhere and has nonsensical motivations. Even worse is the "sphere-builder" race which was probably supposed to feel enigmatic, but instead just feels non-present. Both were forgettable throw-away races which will probably never be used again.
But, as mentioned many times before, I also thought the casting and character writing was poor in addition to awful story choices.