But who says that has to be the only endgame?
Consider this: one of the features of old school play is that your character develops during play. Characters are often pretty sketchy at 1st level, with few details; playing the character helps you develop your backstory and your goals. For fighters, that goal is often "build a barony", but we have a non-political example for wizards (create magic items.) Why not allow players to substitute other long-term goals in place of those goals?
If a PC has a large, mundane long-term goal, such as establishing a trade route or guild or marrying into royalty, assume that the goal can't be accomplished until 9th level. The PC can begin work towards the goal at any time, but there's no permanence or sustainability until the character reaches the reputation, sustainability, experience and instinct represented by 9th level.
If a PC has supernatural assistance to achieve a mundane goal, there's a one-level bonus; in other words, the goal can be accomplished after reaching 8th level.
If a PC has a long-term supernatural goal, such as apotheosis, the goal can be completed after reaching 11th level.
Achieving the goal will also involve several in-game (role-playing) actions. The goal may be achieved quickly, or may take a while; there may be setbacks along the way. If all the necessary in-game tasks have been completed before the minimum level, a complication arises, which the PC must resolve. If it is resolved and the character is still not at a high enough level, another complication arises.
Resolution of tasks may involve dice rolls or may be pure role-playing, in much the same way that lesser tasks (disarming a trap) may involve either.