Oh, it's hardly a great burden - certainly not enough to stop me from getting physical games - but when you're doing it a couple times a day, every single day, it gets old. Especially since I tend to get distracted while I'm doing it. I'll take out both game boxes, set them down, go off to do something else, and forget that I haven't actually swapped games. Or the reverse: I'll switch the games, run off, and when I come back and am ready to play, I'll have forgotten that I've made the swap, so I'll switch games again, then realize what I've done and have to swap cartridges again. You could say, "well, you could try looking at the games when you switch them so you know what you're doing"...and you'd be right. But I often switch games in the dark, so I only have my memory to go on.
I fully realize that these problems are 100% my own creation.