Leareth isn't sure what the final end state is! The really short simple encapsulation is that he thinks all the sentient beings in existence ought to be free to flourish and improve themselves and go towards what they want, but he thinks it's an open question what that looks like once all the stupid problems are solved, because this has literally never happened before. He's hoping a god can help everyone resolve confusing ethical questions such as, whether it's the average level of flourishing or the total amount multiplied across number of beings that matters the most, which affects how high a priority it is to try to get off the planet and expand to the other worlds he's pretty sure are out there and reachable by magic in theory. Also he's not sure if a world where everyone actually has the autonomy to pursue what they want without material scarcity would still involve hard-to-resolve interpersonal conflicts, and what to do about this – there's probably a 'free to pursue your flourishing except that you can't kill other people or destroy their stuff or prevent them from pursuing their flourishing' in there, which a god could maybe help administrate somehow. That being said, if they can get to a state where people actually have the space and time and resources to focus on this for a nice long time, it seems possible that they can eventually resolve thorny ethical questions as a civilization without directly needing a god's help.
There are some prerequisites to these even being the important questions, though, such as 'no one is starving' and 'no one has to do constant backbreaking work with no slack in order to not starve', going up to 'scarcity of resources isn't particularly a limitation anymore'. Leareth doesn't so much need a god's help with this, as need a god's help to negotiate with the existing gods on their own level, figure out what sort of problem they have with this concept, and get them to stop interfering, though he certainly hopes a cooperative god can help solve the stupid problems faster and maybe without all the intervening steps that require decreasing people's freedom and autonomy because they're currently doing dumb harmful things with it (or, well, sometimes murdering some current people for blood-power in the name of solving things for future people). The list goes on to cover 'no group of people and all their descendants are bound in a pact with an existing god that forces them to do a particular thing forever' and 'no existential threats on the horizon' (there's some sort of centuries-from-now cataclysmic event that he's pretty worried about, which isn't described in detail), and go up to 'death is optional'. Leareth thinks this ought to be feasible via modifying the current afterlife-and-reincarnation situation to be less lossy and allow preservation of memories and sense-of-self across different bodies, if a god was willing to prioritize this.
There are probably still a lot of hard questions at that point, but it's an alien enough world from the current one that Leareth is hesitant to speculate on what the next improvements would be. He isn't a god, after all.