The Black Panther has scenes that are vastly different in tone. The movie as a whole? Not that far off from generic MCU film, which is where GotG orbits. One leans into the comedic elements, one has a few serious moments and scenes, but at the core they just aren't that different. As an entire experience, they share more tonal similarities than differences. In my opinion, you can differ on that (and go on and on about DC's serious tones as if Snyder still matters in anything).
(Also you are legit crazy if you think most of the complaints about the DCEU aren't piled on MoS/BvS/SS/JL - seriously, don't let your debates with Snyder fans color your views about which DCEU films actually get pissed on.)