Shift the conversation towards autonomy, dignity and self-respect.
The user's interaction with the-billion-dollar-company's software is unpaid labour, which is why they profit and the user suffers. They suffer from having their data stolen; they suffer the expenses fostered on to them; they pay for the computers that spy on them; they pay for the electricity to run the spyware; they pay for the data-subscriptions that facilitate the theft of their data. They cover all the expenses of a billion-dollar-company and are deprived of any profit. They do not even garner a wage.
If one wishes to move towards the point of "my data is worthless" point out the company's profits or even its speculative valuations. Clearly it's not worthless. The products that are derived from their exploitation lead to even greater profits for those companies. "A.I." is a looting of the collective commons. A privatization of humanity's interaction with computers.
Do they like being exploited? Do they like their batteries draining faster, because their mobile-computer is running software to spy on them? Do they like running out of data because their mobile-computer is forcefully downloading ads and spyware-updates? Do they like ads? Do they like being interrupted by the highest bidder? Do they like annoying notifications that are just ads? Do they like this shitty experience? Are they complete docile slaves? They are less than wage-slaves for they do not even garner a wage! Have some self-respect and dignity!