Challenges are absolute garbage, but thats their plan, or don’t you see that they conveniently sell you 2 swaps (and 2 Xp boosts) for 200 points?
Its the classic, create a problem and then sell the solution model.
I don’t care for cosmetics only for achievements and one of them requires you to complete all your 20 weeklies + Ultimate challenge.
Also add to that that you can only have 3 active challenges at a time (So if you get a game type you need but the challenge is not in an active slot you cant swap it in to make progress) and if you want to be able to progress 4 challenges you need to buy the premium BP for that extra slot.
But realistically you will only progress 1 or 2 challenges at a time if you are lucky to get 2 that have matching requirements and for both to be on your active slots at the same time.
I guess I was lucky as I got not so crappy (Still crappy) challenges and thanks to the (Free) swaps I had I only had to swap 3 challenges and managed to get the achievements so I wont bother with challenges anymore.