sure, sometimes it's unavoidable when there is real value added in using these platforms. at the end of the day most of us have to entrust our infrastructure to some hosting provider. I trust a provider I pay (with a known privacy policy) more than a public CDN (with a privacy policy that allows them to make money in unspecified ways)

but yes, centralized ssl termination for distributed systems is an issue that's difficult to mitigate WRT privacy. maybe via https://en.wikipedia.org/wiki/Multipath_TCP ? i don't know enough here.

> using a browser by an ad company

this is up to the user