This is why the only viable solution to giving existing people a sense of purpose/meaning is to create a bunch of new people who aren’t as driven by status. That way every existing person can be as impressive within their particularly community as they want: Since most of the other people living with them have little drive for status and don’t care about getting fame or needing to feel like they’re exceptional/special in some way.
Then combine that with simulations DM’d by superintelligences and you really should be able to give every person the feeling of being maximally fulfilled in their life.
Since the admiration of the people in the simulation who see you as a hero can be totally real. With those digital people you will become close to being made as real digital minds. So your relationships with them aren’t fake. With them having preferences such that once they find out they were made with a fabricated backstory/memories within a simulation they aren’t resentful: Instead being actively glad they got to think they were really say saving the world with their best friends, and with any hardship faced being stuff they see as worth it for the personal growth it gave them.
The issue with running people at different speeds as a solution is that the eudaimonic rate for people to increase their intelligence will vary, however this creates an incentive for people to self modify in a sort of race to the bottom. It’s also problematic because people are liable to care quite a lot how fast they’re running, so this forces society to splinter in terms of who can interact with each other.
Also at a fundamental level it seems like what you’re reaching for is still going to end up being a Federation style caste system no matter what: What I mean by that is that there will always be some people who are the most competent because of a combination of where they started and how fast they were allowed to improve themselves. Which means that the people who are less competent than them will know that they are always going to be in their shadow, which seems guaranteed to breed resentment.
In contrast you could let everyone enhance themselves to then same ever increasing baseline standard. However this would essentially make it impossible to every achieve anything or stand out at all except through luck or having already been famous pre-singularity.
I don’t think there’s a good solution here that doesn’t involve creating a huge number of new minds that lack the same zero sum desire for status that most (but not all) humans have. That way all the original humans can be as special as they want (unless they only want to compare themselves to other original humans) and most people don’t desire status enough to feel like they’re missing out on anything. With these new people created to be maximally fulfilled without needing to be special or accomplished in some way.