Well, not necessarily. I've had my phone for almost five years now. The battery is at 78% of it's original capacity and still gets me through the day without problems, even on heavy use. The only times I need to charge during the day is when I'm on a long distance train and listen to podcasts or audio books for hours.

Chances are that something else will fail long before the battery. And even if not, the local phone repair shop offers a battery replacement for about 50€ which is more than reasonable for something that will get me another couple of years.