Why? We're still talking about capacity, right? If else, then I don't get the joke, sorry xD
There are much like this, but not as low price as this one in particular. I got it on ebay.
ebay + €5 + no brand + advertised as 30Ah.
That should ring all alarm bells, especially when xiaomi/anker/ravpower powerbanks of 20Ah capacity cost about €20-30.
This is why exploding powerbanks are still a thing
20,000mAh to 30,000mAh is pretty much the norm for the bigger batteries.
I know, just the €5 + ebay triggered me