I agree. Some subset of ADAS are using things like LIDAR mapping data that do incur ongoing cost. For example, Ford relies on road having recent LIDAR data to let you take your hands off. So they have a subscription, and if you don't pay... Well it's almost the same except your hands have to stay on. It is vaguely less competent, but still pretty much follows the lines/traffic on its own.

Of course their pricing is way more than I think will work out, but I can at least understand why a subscription fee is associated.

The argument I could maybe see is that their seemingly fine ADAS system is at higher risk of being hit with a mandatory recall down the road. Those generally ignore all warranty limitations (e.g suddenly having to replace airbags in 15 year old cars...), but might spare them the expense for those who lack the features, or at least the revenue from the users helps fund the possibility of converting a related recall.