What's special ammo in Destiny 2?

In Destiny 2, special ammo weapons use a different type of ammo due to their higher damage or specialized use. Special ammo weapons include:

• Shotguns
• Snipers
• Fusion Rifles
• Breech-loaded Grenade Launchers
• Trace Rifles

Special ammo appears as green ammo bricks when killing enemies, but will only drop if you currently have a weapon that requires special ammo equipped. When starting a new activity (such as a story mission or a strike) the game will make sure you start with a small amount of special ammo if you have one of these weapons equipped. If, however, you switch to a special ammo weapon during an activity then you will need to defeat enemies to obtain special ammo.

Special ammo weapons can be worthwhile in PvE due to their higher single-target damage potential, making them useful against tougher enemies. In PvP, special ammo weapons often have the potential to kill opponents with a single shot.

The game will only drop special ammo, if you have a weapon equipped that uses it.

It's also worth mentioning that if you are on a planet, and switch to your special ammo weapon you will always start with 0. But if you for example go to the traveler/the farm first equip the special ammo weapon, then go to a planet you will always start with some.

If it is worth it is all dependent on your gameplay. If you like using snipers then yes because snipers use special ammo.

Also weapons like the coldheart and the prometheus lens use special ammo, they are fun to use and very good in pve.