Writing might be inferior to lifelogging as a way of preserving yourself, but it might actually be better than lifelogging as a way of having a specific type of impact on the future. Since neither form of reconstruction is going to provide the same type of experiential immortality as cryonics potentially would, why not attempt to reincarnate your ideal self?

(As far as general anthropological data goes, there's going to be plenty of footage of average schmucks doing random stuff.)