you should add a setting in game setup that gives all weapons and perk
what's the point of progression system when you can skip it? Best weapons are unlocked from very beginning. If you think you are losing because someone has "better attachments/weapons", then i will disagree. You are losing because other players are better and getting more attachments will not change anything.
You can always go and play GG, or TGG, where everyone has the same weapons and attachments.