The accounting, legal and business process requirements are vastly different at different scales, different jurisdictions, different countries, etc.

There's a crazy amount of complexity and customizability in systems like ERPs for multinational corporations (SAP, Oracle).

When you start with a small town, you'll have to throw most of everything away when moving to a different scale.

That's true for software systems in general. If major requirements are bolted on after the fact, instead of designed into the system from the beginning, you usually end up with an unmaintainable mess.

Knowing that the rules for your first small deployment are not the same as the rules for everywhere, is valuable for designing well. Trying to implement all of those sets of rules in your initial deployment, is not a good idea. There is a general principle that you shouldn't code the abstraction until you've coded for the concrete example 2 or 3 times, because otherwise you won't make the right abstraction. Looking ahead is not the same as starting with the whole enchilada for your initial deployment.