Prayer obtains what it is due to obtain — not what I personally want to obtain, which is different. It is useful that islands of prayer exist in the world, even if they are composed of only one person, or two, or three, or four.
There are great treasures in the soul: there's faith and love, there's awe and wisdom. All these things you can dig — but if you don't know where to dig, you dig up mud. If you want to get to the gold — awe before God, and the silver — the love, and the diamonds — the faith, then you have to find the geologist of the soul who tells you where to dig. But the digging you have to do yourself.