i think it comes down to: 1. the majority user base does not care and/or is not willing to pay for the ads 2. these platforms/products do not want to cater to

i think it comes down to: 1. the majority user base does not care and/or is not willing to pay for the ads 2. these platforms/products do not want to cater to the minority that cares about their privacy and not being exposed to any advertising