Hybrid is superior quality copolymer nylon monofilament, coated with a micro thin layer of fluorocarbon. The 2 bonds of materials combine the high performing characteristics of both materials.
Strength / Diameter Copolymer is easy to knot but loses up to 20% of it's strength when wet. The fluorocarbon coating maintains the wet strength of the tippet which means you can fish a tippet up to 20% thinner than you could if you used pure nylon. Fishing a thinner tippet means that you can fish smaller flies, more naturally and spook less fish.
Light reflection Light reflecting off the clear surface of tippet spooks fish. Hybrid has a very slight grey tint which reduces light glare by 60% which results in more fish hooked.
Abrasion resistance Fluorocarbon is more abrasion resistance than nylon but is also a little stiffer. Combining nylon and fluorocarbon creates a supple but robust tippet material that will not break when fishing over snags. Essential when nymphing is boulder strewn rivers.
Knots Pure fluorocarbon is very hard to knot. Heat builds up and snaps the tippet. Nylon is very easy to tie. Combining the 2 materials means you can benefit from all the features of fluorocarbon but still tie knots very easily with cold / wet hands.
Stretch Fluorocarbon stretches less than copolymer. Hybrid stretches less than pure copolymer because it is coated with fluorocarbon.
Spook Less. Hook More. Land More.
Silk fly lines are much thinner than PVC floating fly lines. It's no coincidence that older cane & bamboo fly rods had smaller rings. They were also softer in action due to the materials. Rods didn't need all the power they have now because the lines were thinner and cut the air much more easily.
Reducing the diameter of the projectile has a profound domino effect on all the other components of the fly fishing system. If the rod you are using is now softer, you have more shock absorbency in the fly rod. That means you can use lighter tippets, which generally means you spook fewer fish and hook more fish. The rod bends more and protects the tippet so you land more fish.
Try terms like "sinking fly line"