Fuchsia may not be outright dead, but it's definitely on life support and would've been killed a long time ago if senior people at Google weren't personally backing it.
It had great foundations but without a concrete use case or product development was constantly pulled in different directions. It seemed like every year a new niche for Fuchsia was on the horizon, 6 months of development time would be dedicated to it, an extremely hacky demo would get the public hyped up, and then the whole thing would be abandoned because it didn't make any business sense.
Starnix, for example, has been completely deprecated. There was even a newer system to replace it which also got cancelled.
* My knowledge is a couple years old at this point and I haven't kept up with recent developments so maybe the future is brighter than I think.
So the hope is that Starnix can emulate Linux syscalls well enough, while gVisor has been abandoned in later Google Cloud stuff because it couldn't emulate Linux syscalls well enough. Uh-huh.
Several operating systems successfully provide a Linux emulation mode. gvisor has very different constraints and requirements. It's also still heavily used and under active development so I'm not sure how you determined it is abandoned.
Posix lite didn't lose favor. It's still an important part of writing fuchsia native software. It enables us to use the c++ and rust standard libraries with minimal upstream changes. It was never meant to enable running all existing programs, only lowering the barrier. There isn't really much software that has been ported to run on fuchsia natively. Instead runners are implemented or ported and those provide the environment applications require. For instance a flutter runner, web runner (chromium), and starnix (a Linux runner of sorts) provide the basis of running many existing applications.
But the historical perspective is that Starnix is a relatively recent addition to Fuchsia. Even though Fuchsia is roughly 10 years old now, Starnix has only been useful for about 2 years (RFC 4 years ago)
Before Starnix came along to help run Linux apps, as you said, “There isn't really much software that has been ported to run on fuchsia natively”. Because POSIX Lite wasn’t / isn’t being used much. So I guessed the OP could have been thinking about that. But who knows.
* My knowledge is a couple years old at this point and I haven't kept up with recent developments so maybe the future is brighter than I think.