Most of the players who constantly feel like they're always searching for things in Starfield such as Sealant or Structural sadly aren't even aware that there's a much better route to gathering Organic Resources than raiding other spaceships or constantly checking Vendor shops. This route, of course, is utilizing Greenhouses, a module of the Outpost building system where players can grow their own alien flora to produce all sorts of different materials.
Starfield: Outpost Greenhouse Guide
Those finding themselves constantly lacking in Organic Resources in Starfield absolutely need to look into Greenhouses and how to set them up.