If this gains widespread use then the transparency points will make it far worse for privacy than using Google.

Why? Google have access control over the data or view it in anonymised form when crunching. But this data will open to anyone and would allow people to correlate visitor sessions not just on a site but across other sites that use this, to the degree that you could start deanonymising the internet activity of people.

It's a strange world in which we can say, "At least today only Google has the data and they've made it hard to get to".