I have owned both Gen1 and Gen2 models of the ZS EV over the last four years.
Prior to that, we had a VW Golf PHEV.
It had a reported predicted range on the GOM of about 30 miles, after a full charge for the first 12 months of ownership from new.
Then it dropped down to 29 miles of predicted range at around 12 months and then reduced to 28 miles the following year.
At the fourth year, it only reported 27 - 28 miles of predicted range after a full charge.
The car was charged from our home wall box as often as possible of course.
Battery degradation was definitely a thing, but having the back up of a fossil engine eliminates any range worries of course.
Other owners of the same car, reported similar declines in estimated range over the same time frame and milage covered.
Small packs, with constant regular charging cycles may contribute to this effect ?.
I really did like my time owing a PHEV, but in order to maximise the efficiency / economy of these heavy cars, you need to be charging them at every opportunity.
They are not so economical without the help / assistance of the EV side of things TBH.