Not gonna write a massive review abt it since I don't have that much time (And it already kinda feels like I've wasted time watching this film)
I'm just here to say this. My expectation of a Nolan film was much higher than what I got, considering the fact that both Inception and Interstellar are genuinely great films that I loved the experience of watching them. Tenet, however, didn't even come *close* to the epicness of those 2 films.
If I had to guess the reason for this, then I'd say...
It's because Inception and Interstellar are both based on concepts that are not exactly proven to be impossible scientifically. But Tenet is based on a concept that is theoretically proven to be impossible. Namely, inverting entropy and/or backwards time travel. Which is why forward and backwards time-travelling objects existing in the same space is completely ridiculous and why it doesn't make any sense whatsoever.
I'll end it by saying that this movie will be forgotten soon, unlike Interstellar and Inception.