Takt Op. Destiny had no reason to be an actively bad show, if I were to make an apt musical comparison, I'd liken it to an orchestra that starts with a beautiful melody.
Eventually, however, as the performance goes on, many of the individual performers begin to miss their notes, until not even the conductor can keep the tune together, and it fades into an incomprehensible mess.

At the beginning of this show's airing, I thought it actually had a lot going for it, the setting in midwestern America felt like a refreshing breeze compared to the usual "random small town in Japan". Even as someone from the east coast, I preferred this to the later scenes in New York. The music went in a unique direction too, adding small flourishes of piano to the battles, and the opening was actually my favorite of the season. The character dynamics were basic and predictable but enjoyable to the point where I could say I was having fun whenever a character opened his/her mouth. Takt and Destiny's beginning antics as foils to each other worked well, and Anna served as a great character to ground the audience. The worldbuilding was the least impressive part, a basic apocalypse setting with the added quirk that all music is banned, or at least extremely dangerous to play. The concept held promise for future character drama in the lives of some of the civilians Takt and Destiny have to protect.
Where does Takt Op. go after this?
After the first 2 episodes, the orchestra begins to miss its notes, Takt and Cosette's backstories are unremarkable and with very little drama that can't be found anywhere else, the setting begins to feel more like a basic apocalypse, and the realization that the whole shtick of "no music" actually doesn't change all too much. After Lenny and Titan each character introduced is actively bad, I could describe each in about two words based on their tropes.
But none of these blunders can destroy a piece combined as long as the core concepts stick, and this is a mobile game adaptation, they'll probably throw about 20 characters our way. Maybe something else will hit.

The show then proceeds to double down, seemingly intent on focusing on the absolute worst parts of itself. Revisiting it for a review. I mistakenly believed it was 24 episodes instead of 12 because each one dragged on so long. Every interaction is just similar tropes repeating over and over. Fights no longer hold meaning, no technique is used, just colorful characters swinging blades and/or shooting at each other.

The same tracks are repeated for the same "dramatic" moments. Takt and Cosette undergo some basic character changes in the middle of the series, but then stagnate in the final few episodes. Their characters in the finale are 10 times less interesting than the ones we saw in episode one. It is like the show goes out of its way to destroy the enjoyable relationship between Takt, Destiny, and Ann. In episode 12, a major character development takes place between Takt and Ann. This exchange completely destroys the effective character dynamic I mentioned at the beginning of this review. If you have watched any number of action anime, you can probably guess what happened just from my vague description.

All of these complaints are just exemplified by the fact that the overarching plot doesn't create any suspense. Most objectives are nothing but a goal that matters only to the characters, and not the audience. This is especially bad in the finale, where the final enemy is so vague and unthreatening that there was nothing to keep me motivated to watch the show to the end.
There was only one character arc that could grip me throughout the show. Lenny and Titan's arc keeps their fun relationship together and builds upon it. The conclusion is satisfying and gives extra meaning to the actions of both Lenny and Takt. But as soon as that arc ends, the characters go on and never mention it again.

As a viewer I feel cheated and like I wasted time in vague hopes that I would be rewarded somehow. But all I got, in the end, was a show that ended up looking nothing like how it began. Takt Op. Destiny is a perfect example of the worst parts of Shonen anime, all condensed into one.