Talking about power banks, it looks like Alibaba only sends cells when they are either in a flashlight or shipped with a charger. I needed couple of 26650 and with that I had to purchase a charger which is a copy of Liitokala two bay charger (has microUSB input instead of USB-C for the real Liitokala) which claims to work as power bank. I was hoping to use this to measure output of a cell but it shuts down very quickly with the cells I have tried.
https://www.alibaba.com/product-detail/LiitoKala-Lii-C2-Smart-Charger-suitable_1600831752747.html
Shipping lithium batteries can be a fraught exercise, so some sellers won't bother with the potential hassle of selling and shipping them. There a lot of rules, and even with them in place, shipments that conform can be arbitrarily rejected.
Sellers that still make the effort to ship cells, do so inside lights, or other devices, to exploit the loopholes that do allow them to be shipped as part of assembled devices, but not as loose, bare cells. That's why they arrive with the "bonus" items.
And in doing so, it also tacitly reveals what those cheap zoomie flashlights, that the neophytes pay dumb sums to buy on Amazon, are really worth, if they can be used as sacrificial packaging vessels to sidestep the shipping regulations.
Potential shipping issues, plus the unknown risks of rewraps, encourages buying from domestic suppliers instead, like Illumn, Li-ion Wholesale, 18650batterystore, and Mountain Electronics.