I think forcing people to be prepared for a day each week without any services (grocery, gas stations) would lead to better emergency preparedness in general. And better planning. (I still remember when people needed to withdraw cash during bank hours and thus had to plan ahead.)
I'd also be curious what the Sabbath would be. Sundown Friday to sundown Saturday? Saturday only? I believe the Christian conflation of church day with the Sabbath is a misapprehension of scripture, but ¯\_(ツ)_/¯
Eh, I don't think so. As mentioned above, almost all stores are closed in Germany on Sundays (not gas stations though, they will sell you emergency groceries for 2-3 times the usual price), and I don't think Germans are prepared that well. I think the frequency of natural disasters is more important for that (we have basically none in Germany).
As an aside, we observe a day of fasting (atonement) every year, so my kids all know what it's like to be really hungry, but they also aren't afraid of it either. There's real life skills and strength gained from this.
I'd also be curious what the Sabbath would be. Sundown Friday to sundown Saturday? Saturday only? I believe the Christian conflation of church day with the Sabbath is a misapprehension of scripture, but ¯\_(ツ)_/¯