You shouldn’t need to worry about getting bad batteries. Since it’s priced at an Ah/month basis (there are also km ridden per month plans), you can swap batteries whenever you feel like it. It is on Gogoro to maintain the health of the batteries, and swap in new ones when they go bad (or upgrade battery versions!).
I mean when I use the scooter less frequently (maybe I got a bigger car) or live somewhere else doesn't have the station, thus canceling the subscription. On that, I guess I will be stuck on the last battery set I swapped in.