It seems like their long term bet is that people who use LLMs to build in the niceties and extra polish will attract more customers, and the race to do this increases overall usage. As if they're saying "subscribe or your competition will eat your lunch".
And until the cost of running LLMs exceeds the cost of someone's salary, people will continue their subscriptions.
But they do more than enable the superfluous add-ons, and have been inserting themselves as being mission critical in securing software. "Subscribe. Or else!"