It's not just solo players, it's all players that are facing the same leveling throttle you reach after hitting the soft cap of 345. I personally went up 2 light levels from weekly engrams, so it's going to take a while unless bongo is planning on giving us other avenues like IB / Faction rally. Clans engrams, exotics, quest drops, vendor rewards, purple engrams are all tapped out at 340. Which doesn't leave a lot of room to upgrade your gear? It's a bummer for sure.