with opening is better? king's gambit or queen's gambit

It’s apples and oranges to me. Kings Gambit is a sharp double edge sword that leads to fireworks and decisive endings; often crushing.
Queens Gambit isn’t really a gambit ironically.
Queen's gambit can intuitively crush a player who plays the Slav Defence with not much practice from the black side. QGD, on the other hand, probably makes the game less complicated for both players compared to a sharp King's Gambit.

Yeah you often come across many people who try to accept the Queen's Gambit from black without much knowledge. Although, accepting the QG is not losing in any measure you must know the continuation. If you try to defend your extra pawn and play into variations like the Greco variation of the Queen's Gambit Accepted you'd most likely get crushed as black .
That's why I prefer Queen's Gambit. Even if it gets declined you must know the Slav and both the QGD well to equalize. One trick I used to counter the predictability of QG is Kingside pawnstorm and QUeen-side castle or no castle at all... Works like magic under 1600

Also according to me the Semi-Slav is much more solid than both the Slav and the QGD; especially Nd2 line. If you are playing an ultra-attacking player; I prefer semi-slav to annoy him/her and when you get your chance you can punish them.
Also special mentions of hyper-aggressive lines within the Queen's Gambit are the Merran variation and the Moscow variation( You should look at the game between Kramnik vs Gelfand in the Merran variation it's an excellent watch

Even if it [the QD] gets declined you must know the Slav and both the QGD well to equalize.
Why would Black need to know an opening well, that he has chosen to not play, to equalize?
Under 1400- King's Gambit because there are traps which people fall for.
Above 1400- Queen's Gambit because its a solid opening

how is this even a question look at how strong the queen's gambit is:
That's Botez Gambit, not the Queen's Gambit
how is this even a question look at how strong the queen's gambit is:
That's Botez Gambit, not the Queen's Gambit
True.
Choose