How about the other perspective?

The current modus operandi for tech companies is to offer something for free or below market price, gain a userbase, lock them in and destroy competitors who don't have cash to burn, then alter the deal.

If I start using a company's offerings, I have certain expectations, such as the terms and conditions suddenly not changing from under me. Now, you can argue that they are required by law to inform me of any changes to the literal Terms and Conditions. Well, yes, except:

1) They are often worded so carefully from the beginning that they can start doing something exploitative at a later date, only after gaining goodwill and users by not doing it.

2) I can't very well stop using a service if doing so incurs a loss to me. Phone operators are required by law in some countries to allow customers to transfer their phone number to a competitor. I am not aware of a similar law for email addresses. And email is at least 1:1, what any other operator offers it technologically compatible due to open protocols, so a transfer is possible. There are services with no 1:1 alternative.

( Hopefully Open Social will change that but we're not there yet: https://overreacted.io/open-social/ )

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There's also informed consent. Most countries don't allow people below a certain age to have sex because they might not understand all the implications and consequences. How many people do truly understand how tracking and profiling works, the risks of data breaches, doxxing, stalking, surveillance, etc? I argue informed consent cannot be formed unless people are aware of _exactly_ where each bit of data about them is stored and accessed; and also are made aware of the probabilities of all the possible adverse events over their lifetime.