If the 2019 algorithm is only useful for "galactic numbers" that's really neat because it will help a lot in the future as it seems like computation is only increasing in scale.
If it ever had the slightest chance of being useful on Earth, it would not be called a "galactic algorithm". In this case that algorithm might be more than galactic: there isn't enough matter in the observable universe to build a conventional computer able to execute it.
In fact a computer executing it would be so large that speed of light would be the main constraint limiting execution speed, not theoretical algorithmic complexity that ignores data locality.
In fact a computer executing it would be so large that speed of light would be the main constraint limiting execution speed, not theoretical algorithmic complexity that ignores data locality.