Yes, I believe in terms of complexity and the need for more tactics the superior sport is American Football. However there is another reason why soccer (its football) is for me a much more enjoyable sport to watch then American Football.
First: I believe that soccer gives players more moments to shine, to show off their individual skills and to show off a bit. American Football on the other hand, although it has its moments, it can be kind of boring?
Second: Length of the game. American Football by all standards takes way to fucking long man. They have timeouts every other play+ time for offense to move out and defense to come in. Soccer on the other hand can be enjoyed. You watch the 90 minutes, (or 120 minutes depending on game) and your done. You can enjoy the rest of your day.
Third: The tense moments. I feel like one of the main appeals of soccer is the tense moments when it becomes up to the GK. Does he pull off a miracle save? Does he fail the team? And so on. It all relies on those tense moments that makes soccer so appealing. On the other hand American Football is a sport where you will most likely be tackled and people can see the tackle happening before the tackle even happens, unless the occaional acrobatic jump comes out which is pretty rare.
Fourth: As an EPL fan. English club soccer chants are the absolute goat.