Historically, this made much more sense. RAM was incredibly scarce as were CPU cycles and the hardware was often tied intrinsically with the software so a modification later down the line was a really big deal.
With modern higher-level languages and scalable cheap hardware, this motivation should have gone away and we should be writing code that is relatively easy to re-factor.
If I don't know that we will need this thing in the future, it doesn't go in. Simple. If 6 months down the line, we now need to add the new feature, I like to think that my code is largely maintainable enough to refactor it to add the feature.
The only exception I can think of is where something is designed to be extendible like e.g. Instagram filters where you might have 10 when you launch but you know that you will have more in the future so you write your code to allow additional filters to be plugged in relatively easily.
With modern higher-level languages and scalable cheap hardware, this motivation should have gone away and we should be writing code that is relatively easy to re-factor.
If I don't know that we will need this thing in the future, it doesn't go in. Simple. If 6 months down the line, we now need to add the new feature, I like to think that my code is largely maintainable enough to refactor it to add the feature.
The only exception I can think of is where something is designed to be extendible like e.g. Instagram filters where you might have 10 when you launch but you know that you will have more in the future so you write your code to allow additional filters to be plugged in relatively easily.