Yes, you can do something against a good shooter.
1. Take cover.
2. Get help. It's FFA, not duels. You're not alone.
3. Flank the archer. Try to ambush him when his attention is diverted elsewhere.
4. If you're getting hit 4 times in a row, then your movement is too easy to predict. Moving erratically is key to make archers misfire.
5. The farther the shooter is from you, the more room you have to dodge arrows. If you look at an incoming arrow's trajectory and you're far away from the shooter, you can sidestep the arrow before it hits you.
6. You don't have to engage an archer (most fights in FFA are avoidable). Disengage and let someone else take those hits, and then you return to take on the archer.
By your argument, you imply that every kit is either OP or weak (and thus every kit should be removed because they're "OP"). Prior to the update, every kit was strong in some area and weak in another. Now it seems like the diamond armor kits got more power while the rest of the kits got nerfed (wizard was directly nerfed while archer and samurai were indirectly nerfed due to regen on kill).
EDIT: Tip #6.
