My immediate reaction would be similar. I tell myself "In the last 4-5 years we had Fences, we had Moonlight, heck even Get Out!, all these are more significant than Black Panther and arguably far better movies, expecially the first 2".
But I realize the point is another. Black Panther's significance is that it's a celebration. It's not a movie about breaking down the issues of the african american community, about introspection on their struggles, it's not a dramatic representation or an exposè.
Black Panther is about celebrating the beauty and richness of black culture (and black people) in a thriumphant, joyful and bombastic way. It's not shallow, but it's burdening itself with the task of being somber or sad either. What makes BP different is that it's not a "black movie" that focuses on sufference, inequality or anger, but that ultimately says "look at us being magnificient and glorious, and yes, we've not forgotten about all that other stuff, but today we stay winning".
At least that's my perception; BP isn't a movie about the struggle for representation or equality, but it's the reward for the journey. A joyful moment. Maybe I'm wrong, but that's the impression I got from the movie and the people celebrating it.
