I doubt it's the bureaucratic cost (the Transparency part), because Meta can devolve most of it onto advertisers, and with their solution they still have the bureaucratic cost of preventing political ads from being served at all.

But there's also the Targeting part, which prohibits using people's personal data for targeting political ads unless they explicitly opted in. Meta describes this as "people seeing less relevant ads on our platforms." https://about.fb.com/news/2025/07/ending-political-electoral... Of course people seeing ads intended for other demographic groups is precisely the point, to force political actors to present a coherent image of themselves to the public.

The same requirements apply to traditional billboard and newspaper ads, but since those can't do microtargeting by design, they don't lose value as a result in the way Meta ads do.