i'll tell you what you probably already know, and hope that's worth something to you.
Using a bigger pipe ensures that the pipe is not the limiting factor / bottleneck, slowing water flow to such a low level that the pipe itself is a source of problems or constraints.
A bigger (wider inside diameter) pipe enables more flow, since it resists flow less than a smaller pipe does. So you get a higher volume / quantity of water at the output, with less friction noise in the pipes, too. Less noise is a major gain in performance for many people. Quieter plumbing.
Using a bigger pipe means that whatever physical limits your entire system has to contend with depend less on the pipe (number of bends / elbows, total length, total friction loss in flow) and more on
a.) the whole-house pressure at the outset
b.) the individual fixtures you have bought
c.) the total number of fixtures
So, I use 3/4" where there are going to be multiple outlets. There is nothing to lose by doing so. There is everything to gain. This puts the plumbing noise at the outlet. Rushing water noise. Sometimes pleasant, sometimes unpleasant, depending on things that are hard to control.