The atmosphere wasn’t like in the previous Hitman games. It lacked this twisted point of view of an cold, detached assassin, and Kyd’s soundtrack heavily supported that.
The dialogues were informative, yes, offered information, but far from serious. I guess the voice acting contributed to that.
And the point regarding dangerous NPCs is valid also. Targets from pervious games were able to kill you and were pretty lethal. in Season 1 they all just run and tell on you. There was also a shift from people-hunting lords, slaughterhouse parties hosts, porn tycoons, terrorists, and child traffickers to bankers, lawyers, (unstable) scientists, and fashion moguls.
Season 1 is simply, as many put it on this forum before, a Bond game we’ve never had, and the soundtrack supports it heavily.