If only... 🙏🛐🕯️. RFF, the predecessor of SNCF-Réseau, tried to introduce nationwide clockface timetable in 2012, in a very timid, imperfect way. (Marketed as the very first step of a long process...) No sooner had Réseau replaced RFF (2015) than the whole thing went up in smoke.
I think France will inevitably have to address this issue by the mid-2030s. I won't be surprised if we see "France Cadence" at 2035