Last is supposed to reduce friction between the vinyl and the stylus. Several such record treatments are supposed to do the same. The old "Sound Guard" was a dry lubricant designed for the same purpose.
Whether any of these products work to reduce wear is something I don't know if this has been demonstrated. When i comes to long-term effect, it is probably even harder to tell. How long does one wait in such a comparison? Could the product ultimately reduce record life if it unfavorably alters the record surface in the very long term? So far, records I have treated with LAST or Sound Guard are in good condition, but, so too are records that have not been treated.