First up, a totally unbranded 5V 2A wall wart. Started at 5.05V at 500mA and stayed dropped to around 5.02V at the full 2A load, with no signs of distress.
Next up, a HuntKey 5V 1A wall wart, from a large, well-established Chinese manufacturer, started at 5.20V and stayed pretty constant at that voltage up to the full 1A load.
Finally, a DVE 5V 2A wall wart, a Taiwanese company operating in Shenzhen but possibly cloned given the number of dodgy-looking units on Aliexpress, started at about 5.05V but sagged to 4.90V at full load.
Interesting that the dodgy no-name brand had great regulation while the DVE one sagged quite a bit. Might toss that one since it doesn't say good things about the overall design.