The unfortunate answer is that it’s coming, and in the form of the Web Environment Integrity API, aka device attestation. If/when they manage to deploy this to enough devices, they will be able to restrict viewing to only allow ”blessed” clients. It needs hardware-level support, and that has been rolling out for maybe 10+ years now in the form of TPM modules and such.

The future they’re aiming for is that unless you’re using an approved (unmodified) browser on an approved (unmodified) device, you get nothing. It would basically turn large swaths of the internet into a walled garden overnight.