I’d say the biggest issue is whether it’s tranformer-based or a switching power supply.

Transformers are less efficient, and waste quite a bit more energy as heat.

You rarely see them these days, but I could see them being sold as the cheap version.

I don’t know of a technical definition of either term that makes any difference. I think those terms are just used to describe how somethings used.

In my mind, power supplies are designed for one specific voltage and wattage output (maybe some variability in current, but only up to the max). Though not the same as things labeled Power Deliver or Quick Charge, which switch voltage levels between discrete, predefined voltages and current levels.

Power Delivery/Quick Charge type chargers are designed with circuitry that communicates with the device to negotiate voltage. Dumb devices (any device that doesn’t request higher voltage) will just get the standard USB 5v (and whatever current the charger supports at 5v).