The two biggest failure points on chargers are The cables, they get trashed, cut, stolen, etc and the rectifier packs inside them, or the DC modules as they are called in other industrys. Those run at pretty much 100 percent load all the time and take a beating, BUT they for the most part, are plug and play, the card pops, a red light comes on, the tech removes the card, and plugs a brand new one in. The old card, not sure if they refurb them or not, I have seen them have a core charge and then no core so ::shrug::
Most of the damage to the cards is heat generated, an SCR gets hot and cooks a spot, burns it, ok that can take the card out for good, the other common fault is a cap blowing. those can be replaced fairly easily.
The third, and not too common fault is fod. Water gets in and shorts shit, the mud daubers nest in the vent holes, and/or drop dirt on shit in there which bridges something short, fire ants dig in, and eventually expand their mount phase to phase, stuff like that. Let's not forget the rattlers and swingers either (scorpions).
Credit card readers can be an issue, Jim Bob gets tired of his card being declined so drop kicks it, touch screens can get punched out, and network issues.
This stuff is not TOO expensive to fix, but the problem is, uncle sam gave them money to put it in, NOT to maintain it, so when it does break, it's on the owner to fix, no incentives there, and most of them, have not got the thing paid off to begin with, now it wants another 3 or 4 K to fix? yah no thanks.
In reality, the chargers really are not that much more complicated than a fork truck charger, except for the crude comms they have for CCS, (just another card to swap) and of course the higher voltages on the DC side, but you are already playing with 480 on the AC side so not much difference really.