OTOH the controlling way modern software behaves is an US artifact, so the differences are not necessarily clear-cut like this.

I grew up and live in Europe. I support the general idea of "regulation to make everyone safer" being an acceptable choice. At the same time, I vehemently oppose third-party interests reaching into my computing device and dictating what I can vs. cannot do with it.

But as you say, "global platforms with global impact and reach" - and so I can't set up my phone to conditionally read out text and voice messages aloud, because somewhere on the other side of the world, someone might get scammed into installing malware, therefore let's lock everything down and add remote attestation on top.

Unfortunately, the problem is political, not technological, and this here is but one facet of it. Ultimately, what SaaS does is give away all leverage: as users, it doesn't matter if we fully own the endpoints, or have a user-friendly vendor: any SaaS can ultimately decide not to serve a client that doesn't give the service a user-proof beachhead.