Unless you plan on using the primary pressure for something else, it only has to be higher than the highest secondary output.
I use 35 psi, so I can carbonate soda water directly.
Remember one unassailable statistic, as explained by the late, great George Carlin: "Just think of how stupid the average person is, and then realize half of them are even stupider!"
"I would like to die on Mars, just not on impact." Elon Musk