There is not much chance that there will ever be a recreational drug that is not addictive to anybody. Drugs cause relaxation, happiness or energy; feelings people like to experience. Especially those who cannot relax or be happy on their own will always feel the need for these substances, and they will easily abuse recreational drugs.
In terms of addiction, there are big differences between the various recreational drugs. All recreational drugs can make you mentally dependent, but some of them can even make you physically dependent. If a new recreational drug would be developed to make people happy, and this drug would be used by people who cannot be happy on their own because of all kind of difficulties in their lives, these difficulties would still not be solved. Their personal development is inhibited. For this reason, a lot of people smoke hashish every day. They try to get away from all their problems and are stuck in this situation.
Some recreational drugs may not be so addictive, but they do cause physical damage: the number of XTC addicts is not so high, but research shows that use of it can damage certain nerves. When we look at tobacco, the chance of addiction and physical disease is enormous, but the chance of social failure is not that big.
A non-addictive drug should therefore meet a lot of requirements: it should not effect your personal development, it should not be addictive, it should not cause physical damage, and it should not cause social failure.