I'll start by saying that I understand that some people, for whatever reason, are constrained to a Wi-Fi connection. For that I am sorry, and I do not have a solution. But what I would like to do is explain why you should look into making your connection wired to your router rather than over Wi-Fi. I also want to say that I am not a network engineer, and I am not even an expert on the subject, but I have been gaming and using the internet dating all the way back to the 80s, and I've learned a thing or two along the way, and hopefully I can communicate this in a way that most people will understand.
There are a lot of factors that can influence your experience in a game like Warzone that I may not specifically address here. With that said, you are absolutely hurting your in-game experience when using a Wi-Fi connection to play Warzone. It doesn't matter how well your connection performs in other games because not all games use the same type of prediction. Even when they use the same type of prediction, the implementation will vary from game to game. Call of Duty/Warzone practically require a wired connection for a passable experience. That is because this game uses something called client-side prediction with a server-authoritative model. Here's somewhat of a breakdown of how that works (without going too deep into the woods).
Client-Side Prediction: Your console or PC instantly simulates your own movement, gun recoil, and animations locally, which is represented by what you see on the screen as you play. When you move, shoot, or slide-cancel, your game client does not wait for the server's approval to show the action. Instead, it predicts the result to keep everything feeling smooth.
Server Authority: The server remains the absolute authority in terms of player positioning, damage distribution for each player, and hit registration. If your client predicts that you ran through a door, but a sniper downed you before that message reached the server, the server will reject your client's prediction and snap your character back to where you died.
This is why you sometimes will feel like you got hit when you were already behind cover on your end. This is also why we have something known as "peeker's advantage" when you slide around a corner and land the first shots. It also explains why killcams do not actually represent what happened on each person's local machine; they are approximated actions based on what the server decided actually happened, regardless of what you saw on your screen. This is where the term desync comes into play because the actions that happened on your local machine, coupled with the latency and packet jitter of each player involved, and finalized by what the server decided actually happened, may feel completely out of sync with what you thought should have occurred.
Now back to the point. When considering these factors, perhaps you can see how introducing the instability, packet loss, and added latency of a Wi-Fi connection compromises the client-side prediction and server authority model. This results in rubber-banding, ghost bullets, and a myriad of other in-game outcomes that don't align with what you are visually seeing represented.
Counter-Strike 2 uses a similar system, but modern competitive titles often operate on higher tick rates or benefit from sub-tick architectures. Historically, standard Call of Duty servers have operated at lower tick rates (frequently hovering around 20Hz, meaning packets are sent every 50 milliseconds, but may vary depending on the specific mode and updates, based on what I could find online), meaning game states update less frequently per second than titles built strictly for rigid, low-latency esports (CS2 runs at 64Hz meaning packets are sent every 15.6 milliseconds). This means that packets are processed much less frequently on Warzone servers compared to a game like CS2. As you can see, even with a wired connection, there are inherent constraints to the Warzone server setup. When you add Wi-Fi on top of that, as the kids say, "you're cooked."
TL;DR — Playing fast-paced multiplayer games over Wi-Fi sucks because of the added latency and packet instability, resulting in rubber-banding or dying behind cover when you didn't think you should have.