PC parts can’t even go few years without losing backwards compatibility (e.g. cpu sockets changing every few years). Last thing I need is for my physical body to incompatible with the newest and best stuff because I got a permanent implant when the tech wasn’t as evolved. This will always be the problem with invasive technology in my opinion.
Even that wouldn't be unworkable, it would be worse if you're stuck with the brain equivalent of serial ports just before everyone switches to the USB standard.