The problem is the changes you anticipate often are not the changes that happen. Those anticipated-but-not-happening changes waste your time, and also clutter up your code, getting in the way of the changes that do need to be made.
And, sure, there are some things that are easy to anticipate. If you're processing CSV, you may get asked to process arbitrary delimited files next. But the point is 3 - 5 years out, you'll get asked for something the current architecture cannot support and a major effort will be required. You cannot anticipate those and thus should never try to.
But I think it's silly to imagine that there's nothing you can do to anticipate changes and make your code more amenable to change.