As a fan of the older FE games, I still think Awakening is a great game. After Shadow Dragon I kind of lost hope we'd ever see a new entry in the west, and Awakening brought the series back in a good way. The biggest problems the game has are that the narrative is mediocre compared to the series' best games, and they added some game mechanics (pair up) that really ruined the game balance. Otherwise they added some nice QoL features and upped the production values, the characters were entertaining. They built the game around the marriage/children mechanics and it added a nice layer of min-maxing for people, they brought skills back, class-changing was done well this time, etc. Personally I love Awakening, it's one of my favorites in the series in spite of its flaws.
Fates, on the other hand, is such an uneven game. While it improved a lot on the mechanics of Awakening (fixing pair up being the main one), it regressed in so many areas as well. The narrative is just awful. Virtually no world building, there are some good characters but most of them are awful, one note, defined by one trope shells. Thankfully the map design is great, particularly in conquest, and the return of varied map objectives is a godsend, but they dropped the ball when it comes to story and characters, elements that have always been incredibly important to the series. The addition of marriage/children feels like an afterthought, the explanation for it is so insultingly stupid and the child characters are barebones, with half of them just being copies of Awakening characters (the entire cast has this problem). If you couldn't make every character at least slightly interesting, maybe...idk...you didn't need to have so many? The plot is awful, so many contrivances and dumb motivations and hand-waving going on. Imo the best way to play fates is to just skips every story scene so they don't turn you off from the gameplay.