I've been a huge AOT fan since the series first was released. I watched the first two seasons in a few days after the second season was released. This was during a particularly difficult time in my life, and so I attached a lot of value and love to the characters who helped me get through some of the toughest mental health struggles I've ever had to face. I built myself a 3DMG for a Sasha cosplay - it was my first time ever doing a large-scale construction for cosplay and was poorly constructed so it fell apart at the first convention I took it to, ACEN. However, I still had that attachment to the characters and it made me so happy to meet with other fans of the show.
Unfortunately, I don't believe the third season met with my expectations, and sort of tarnished my golden relationship with the Attack on Titan series.
I'm unsure whether it was the fact that we had to wait for so many years and I forgot why I cared so much about the show and its characters, or if it was the season itself just not living up to the wait and the hype. I'm thinking it was probably a combination of both. I know why they waited so long - to keep up with the manga - and I'm glad they did, since I've never been a fan of anime that try to release ahead of the manga, because they're usually full of pointless filler. But I think it was just too long of a wait this time. The hype had died down so much that it didn't feel like anybody cared anymore. I didn't even know the third season was out until a few weeks after.
The way that the show chose to focus on the politics, too, I felt strayed from the formula of what made AOT so likeable in the first place. We liked to see the characters grow and change as they fought these horrific beasts that traumatized them, but also brought them closer. We enjoyed the suspense and heartbreak of seeing our most beloved characters almost die, or actually die, or fake-die. There was genuine concern in the fanbase for characters who were left in a state of not-sure-if-they're-going-to-die at the end of an episode. I felt like that genuine concern had faded by the time season 3 came out. I didn't find myself feeling the visceral reactions I had during the first two seasons when a character would do something outrageous or risky and would end up better for it. I felt like I was watching a historical drama instead.
Amidst all of this, however, the animation. absolutely. slays. The scene where Levi is using his 3DMG through the streets of the city and the camera is moving around him as he ducks and weaves and spins was probably one of the most beautifully animated scenes I've ever seen. This stays true to the fast-paced interesting animations of the first two seasons, and made the show pleasant to watch.
Overall, while the third season definitely was not what I hoped for, it was faithful to the manga, and was still enjoyable to watch. It just didn't capture that 10/10, raw emotional terror and joy that the first and second season managed to capture. I'm not saying don't watch it - it provides necessary closure and wraps up the story nicely, although there are a few holes still. This is to be expected of AOT at this point though - I believe they enjoy leaving certain story elements to fanbase interpretation. Just don't expect to be floored like most people were with the first two seasons.