Depending on how you present it you can potentially get people to keep these kinds of writings even if they don’t believe it will extend their lives in any meaningful way,
Writing isn’t feasible, but lifelogging might be. (see gwern’s thread). The government could hand out wearable cameras that double as driving licenses, credit cards, etc. If anyone objects all they have to do rip out the right wires.
Is a vitrified brain conscious?