I’d take this in reference to the military video that was released rather than “in total” do ufos “exist”. Yes, because the objects are unidentified. No, they don’t have to be aliens.
The Pentagon has admitted "UFO's" exist. The question is what are they and to whom do they belong.
As Marco Rubio has said (as chair of Senate Select Intel Com), it's almost more comforting to believe the ones ID'd by the Navy are extraterrestrial than that they have been developed by China or Russia.