Question

What would happen if there were no saprophytic plants?

Answer 1

If no saprophytes would be there the world would be stinking.The saprophytes eat us or consume the dead and decaying.They work are the cleaners you can say.

Answer 2

Saprophytes play an important role in soil biology. They break down dead and decaying organic matter into simple substances that can be taken up and recycled by plants.

Saprophytes act as efficient decomposers with the warmth and wetness which help to accelerate to decompose and break down dead animals and vegetations within 24 hours.

Decayed matters contain essential nutrients like iron, calcium, potassium and phosphorous necessary for the rain forests growth. Saprophytes as decomposers continuously work to release these and other elements into the soil.
So if it's not there then this process wouldn't take place