Good quality micro USB sockets have a core made of fiberglass - loaded nylon, and the contact stripes made of phosphorus bronze.
The same used on good quality cell phones, they can last tens of thousands reciprocations.
They are not that expensive, maybe 10 cents each, if you buy them in the thousands.
What I have seen used in some mods, are some substandard micro USB connector s, which can last an hundred reciprocations at best.
Same applies to the cables. I now avoid the cheap cables as the plague, including some bundled with devices.
The micro USB connector is not the best suited for a mod. A calculator-type round jack would be the best suited. I have the IPV4 mod which has the round jack connector. It lasts forever.
Problem is, the European Union mandated an universal connector to be shared among phones and other devices, and they choose the micro USB; subsequently, it has became defacto standard worldwide (except Apple devices).
Again, it is not the best suited connector for vape devices. But when some manufacturers skimps on it, that should be pointed at.
Ask the reviewers to check the quality of the connector, and not to hold the game of manufacturers by suggesting the use of external chargers.
Nobody uses an external charger for the phone.