About 3 years ago I played a CoD during the free weekend and had mostly the same experience as you. What I found to be the cause of the problems is that the starter guns have a much higher time to kill than the unlocked and modded guns that the rest of the players were using. Players know to prefire based on the map at the top-left. The game basically has a built in radar hack. You can camp a corner, aim at the opening, and watch the map to know when to prefire. Players who started playing when the game launched and are still playing have memorized the spawn locations and know where to aim to catch fresh respawns.
I started with a $15 double edge safety razor that I used for years. I bought the $70 Henson razor because I wanted a better shave, but the results are about the same as the $15 razor I started with. The Henson razor glides better so I can get the same quality shave with less time. I can also shave twice (one across the grain once against) if I want a better shave, but it still isn’t the smooth shave I was hoping for. The henson razor came with 100 blades, but you can also get 100 blades for $10 on amazon.