GDP estimates from nighttime light data are possible but often inaccurate. Before you even get into the larger issues, there are a lot of small things, such as cloud coverage, ground coverage changes, lunar illumination, &c... that have to be accounted for.
It's great when you're trying to track urban development. It's good when you need quick ground truth estimates (e.g., you're looking at an area impacted by war or lockdown and you want to get a rough guess of the actual impact), and it's ok when you are looking at a country with an economic model (manufacturing/export-led) where changes in nighttime light volumes can tell you something.
It's iffy if you're trying to compare a lot of different countries, with different economic models, across different time spans, and you don't have the time to accurately assess whether nighttime light data is a good proxy for GDP in each of the many regions/country <-> economic model combinations you're looking at.