Good quality 12VDC USB Charger

[john61ct]

When used as a lighter, that high current is very short, just a few seconds.

We're talking continuous amps, a very different context.

Plenty of "accessory sockets" will not stand up to (or even accept) the old lighter plugs.

see ANSI/SAE J563 for that distinction

Plus, as you say the stock contact design is inherently unreliable, aka intermittent, so even at just a few amps, can cause arcing, seen a lot of blackened innards and melted housings even in low current use.