Stickers and charms

All these colorful elements are prepared for the younger generation of players - who want to stand out from other players to some extent (and are willing to pay for it). So producers/publishers give them this opportunity.

True veterans of the Battlefield series have such things in high regard. If someone wants to parade around like a clown on the map, no one will stop them from doing so, they will be an easier target to shoot when they are driving around in a golden tank with "I love mommy" sticker.

Who cares? If you want a more realistic-looking shooter, just ignore such things.

For a company who wants to make money from cosmetics, the cosmetics are awful.  Gun camos and charms and stickers are absolutely pointless as no one can see them, vehicle camos and decals lack imagination and again, mostly hard to distinguish in game, and the uniforms are mostly bland and again, not noticeable in game due to the games pacing.  All have regressed from past games