Every time there's a high profile trade between professional sports teams, we love to have the conversation about who "won" the trade.
In reality, the answer is always the same, at least at the time the trade is made: everybody won.
There are no teams that make trades that they don't think will benefit their team. Nobody is ever making a trade for the good of another team.
When the Rams traded Jarod Goff and two first round picks to the Lions for Matthew Stafford, both teams saw a benefit. The Rams are in win now mode and they didn't think that Goff was good enough to win a championship; and, they were able to unload Goff's contract. The Lions are in another rebuild and know that their chances of making a playoff run this year are slim to none; so, the take the downgrade at QB in exchange for the capital need to build a more talented roster over the next couple of seasons.
Even trades that we look upon as boneheaded moves like the Texans trading a ton of draft picks for Laremy Tunsil made sense to both parties at the time. Buyer's remorse will always be a thing; but, it doesn't change the fact that both parties saw themselves exchanging something that they don't need at the moment for something that they do.
We should really try to learn this because it teaches us an important lesson about economics - free exchange isn't a zero sum game. Every time we make a trade we can expect that we're making each other's lives at least marginally better.