I finally upgraded to a synology nas and I feel a little silly for not doing it earlier.
It's far more convenient given I bounce between 3 machines during the day (personal laptop, work laptop, desktop), my wife can easily access files on her machines as well.
Added bonuses are that it comes back up on its own after a power outage, doesn't require my desktop to be on for me to hit it externally or for a successful backup, and I don't have to remember where I last placed the usb drive.
Basically - USB drives totally work, but the NAS is better in pretty much every way outside of price (and possibly some configuration, if the person isn't very technical).