@JonathanReez I am not privy to all the details of how contact tracing is set up in France (even if I interacted with it recently) but there is a clear bias towards tech solution among tech-loving Internet dwellers that make me skeptical of seemingly obvious improvements that turn out to be anything but.

I work for a company full of talented engineers spurning out pseudo-solution like that with a depressing frequency

Back in March-April, everybody was jumping on this bandwagon, submitting bids to develop apps they were barely qualified to develop, obsessing about technical means to do contact tracing, etc.

Reality is that contact tracing requires human contact to convince contacts to take it seriously and that take hours, not seconds so the win from an already digitized form is not necessarily a game changer.

And it comes with a lot of obvious drawbacks: time lost cheking it at train stations and airports, imperfect coverage/people who have no mobile phones, legal and technical headaches to integrate systems from all carriers or retrofit APIS to deal with highly sensitive personal info, etc.

I don't know for a fact that they are being used sensibly but it seems quite likely to me that a paper form is a reasonably robust compromise for a system that had to be put together in a few weeks

Contact tracing apps were also hotly debatted in some circles so relying on something app-based is just inviting controversy and risking lower compliance/lower data quality for no good reason.

At this point, having seen many efforts like that from the inside, it's the notion that an app/electronic version would necessarily be better that is not obvious to me.

@Daniil, it is very low quality and I converted it to a comment, so it is still there. (And your answer has so many more details that I doubt this 'answer' can ever be improved to better that standard.)