That totally makes sense. The overall ruling (U.S. and at least Germany, France, Costa Rica per my experience) is that all lithium-ion batteries must be in your carry-on only. They can’t be in checked baggage due to safety concerns. There are limitations to the power of each, however.
Here’s an article on CNN from October 2019 that’s a great rundown on acceptable options. I have the second one listed (Anker PowerCore+) and love it; also great for our annual NorCal power outages!
So that’s primarily a ruling in the U.S. Although I have flow in with a variety of camera, drone and rechargeable batteries domesticity and internationally without a single issue. I simply keep everything in my carry-on.