Except if Google gets bored with Fuchsia, like it has with tons of projects.
Heck, from what you say, it already got bored with Android -- if Fucshia is to replace it in say 2022, it means that Android just lasted around 15 years as a platform.
>Android is definitely struggling and showing its age by this point
I have the opposite viewpoint on this. I've worked on mobile the last 5 years or so, and dedicated native Android the last 2.5 years. The last year or two have been dramatic revolutions in the Android developer experience, from my perspective. Things like ConstraintLayout and full Kotlin support with ktx have opened up a new world for me compared to the state of the art several years ago.
Then you look at companies like Peloton using large form-factor Android devices in their core products, and Samsung DEx using Android as a seamless mobile<->desktop computer.
To me it seems like Android is just hitting it's stride. Who knows though, it's Google.
Wikipedia lists the last release of MS-DOS as version 8.0 in 2000, linking to the page for Windows ME.
This is what the comments above were alluding to, a "final release" before the project is abandoned. Installations still continue, in the same way there's probably places still doing the books on a C64, but it's no longer supported.
Heck, from what you say, it already got bored with Android -- if Fucshia is to replace it in say 2022, it means that Android just lasted around 15 years as a platform.