The gutter below the valley is showing signs of rust once the debris was removed.
These gutters are in need of some tender loving care. Over time the gutters have rusted and holes are starting to appear.
Looking at the chimney in the next photo, you can see a tuft of grass poking out from the gutter. The after photo shows there is a down pipe where the grass is lodged.
In heavy down pours this can cause overflow issues to occur. It could also cause water to pool in the gutters adding to the erosion process.
Look at what was actually below the tuft of grass.
This solid root mass was lodged in the down pipe. Water will only soak through this slowly, therefore the gutter definitely held water when it rained.
Now that they are free of debris and the blockage, the gutters will do their job. But they will require some attention where the holes are and regular gutter cleaning to keep them doing their job.