T2 ammo is not supposed to perform well in most situations, it’s supposed to perform well in niche situations. It is specifically designed so that non-faction T1 ammo will outperform T2 ammo in most situations unless certain conditions are met, such as when the enemy is webbed or painted (or out of range as in the case of javelin missions, etc)
Longer range T1/Faction ammo could use some love to make it worth using alongside T2 long range ammo, however.