I download all my games and if I run short of space I just archive them.
I'd hoped we'd moved past the days of fridge cleaning.
But having a hard drive attached to your dock would still mean fridge cleaning when you undock, take it on the go and realize the game you really wanted to play isn't on system memory.
Still quicker to load off local storage than to have to download it all over again.
It would be amazing to be able to dock the system, which will auto back up your saves to the N-Cloud, then you select the games you wish to fit on local storage, the Switch gives you a time frame (ie ~10 minutes) and you literally go do something else, like get ready to leave, and then 10-15 minutes later you come back, snatch the switch off the dock and go.
Games not selected removed, and games selected added for play on the go.