oh my.
Achievements and levels. Well, In a purely multiplayer game, with no gameplay unlocks, achievements and levels are merely little dopamine triggers designed to keep you playing. I get that leveling up is important to alot of people playing, but really that number and title dont mean anything at all. Really "leveling up" in this game is community based. no matter what the number is next to your name, if you are a good, friendly, and helpful player the "top teir" players in the game start to want you playing in their games. (as great as the community is in this game, there is definitely a split between the "in crowd" and the masses, its fading away as more people play the game but its still there and is a fact of playing guns as of right now.) That is how you really "level up" in this game, when the players recognize and respect your abilities in your preferred role(s).
As for actually doing the achievements, I am of the opinion that they are actually too easy, when you stumble across achievements they lose all meaning. they are not really part of the game, they are an extra. and maybe its just because i have played alot of rather brutal games, but i dont see the problem in working in the system set up. If making a number go up is important to you, then great complete the bonus missions available the best you can (despite my upper end levels, i have alot of achievements that i just havent worked on because it be fun for my crew or be helpful to do at the time, though i have been guilty of just saying fuck it and cheeve whoring #buffcheeves)
Making a number go up does not equal fun, that is just psychology keeping you hooked on a product. the fun in the game is the game.