Strong Acid is a crucial material in Subnautica 2 that is required for crafting multiple core blueprints, including a Tadpole, which you absolutely need to unlock in order to progress through the game ...
Some materials in Subnautica 2 can be hard to come by, but Necrolei Cysts are not one of them, provided you know where to look. As an early game material, once you reach them, you can hardly sneeze ...