I've always believed that AXL+IZZY joined SLASH+STEVEN and DUFF as the glue in the middle of two different factions. They may have never lied each other from the beginning but they made good music and began to slowly see success on the Strip like none of them had seen before. That and the increasing $ they made turned them into a band but the bonds were only as strong as the success.
Once they got huge, each had their own ego, $, houses, and drug additions, they easily fell apart. Axl had the most level head and tried to save the name at the cost of the members.