You're right but I hate that you're right. The only part I disagree with is

>I think they all are pretty happy with the deal and would not switch to a paid ad-free version.

If they were given a low friction option to pay the advertise price for these services I think a lot would choose it. Advertisement pays almost nothing per person. Almost every person could pay more than the cost to serve them an ad. To use a service ad free for a year would cost less than $1 per user. This differs on the platform obviously with stuff like youtube being far more expensive but for day to day stuff the cost is low.