If you lived in a rainy climate, and had problems with excess moisture in the pile, it probably would be beneficial. I don't have enough moisture in my pile to justify a leachate collection system.

If you had runoff it would be beneficial, like a compost tea, but I think for most people they won't have that much excess moisture.

If you had enough water flowing from your compost pile to collect it then your compost pile would be too wet to properly, aerobically, digest and it would be in anaerobic digestion and smell putrid and offensive.

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I have long had the tendency to over water. I'm in a dry climate so I'm always expecting things to dry out.

Water draining from the pile represents excess so it's a good thing that it is draining because as kimmsr explained, too much moisture kills the aerobic process.

A better strategy might be to reduce the excess water in your pile. That's tricky because not enough moisture slows things down too. When I'm doing things right, I'm adding a little water at a time on a daily basis. Too much water at once just washes stuff away onto the deck but too little and my piles slow to a crawl. Too much water is a waste and in this dry climate, that's a sin.

to sense
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If you've got that much drainage, your pile is too wet. Too much moisture, too cold, not enough air. Why not save all the extra effort and just cover it so it can do what it should be doing?

Sue

Consider twelve inches or so of wood chips as a base, if you have access to them.

Those who compost deer and other road kill, as well as large amounts of fish parts, do this.

I've started using a thick layer of fine wood shavings. During our dry summer last year I overwatered a couple times after we had been away and had some runoff. The base layer will be used for mulch and replaced every time I empty the bins.

"Keep It Simple" is my motto.