Article misses the fallacy of the comparison. If I buy a cup of coffee, I get my end of the bargain immediately* and no further commitment on my part is needed. For most saas offerings though, I’m basically committing to a regular payment in perpetuity. Usually if I stop paying, I not only lose the immediate benefits, but also whatever I have put into the app in the time I used it. Even if it is just storage, if I cancel it, I have to find a way to replace the storage and the access to the storage from my devices.
Committing to a monthly payment is usually not the same as buying X coffees for a month.
*or close to immediately if it is one of those annoying poor over places