My experience has been the same, I've had a 4 for years and it is still going strong but my 4C died in less than 12 months; the USB-C connector is too flimsy.
The connector itself is okay; it's just that the casing is poor. When it finally breaks apart, I'm going to try to cast the board in epoxy. Either I'll succeed, and it will be (hopefully) durable, or I'll completely ruin it - but it'll be broken by that time anyway.
YK4 (non-C) is quite robust, though.