Many, many languages have already died out. The world has far fewer languages today than it had 100 or 200 years ago, as people switch to using the dominant language of their region.

For example, you probably think of Ireland as an English-speaking country. But until a few hundred years ago, it wasn't. Irish Gaelic was the most common language in Ireland for most of its history; they swapped to English after England took over Ireland. (Gaelic speakers still exist, but it is now a shrinking minority language in Ireland, not the dominant one.) The same went for Wales and Scotland, both of which originally had their own languages (Welsh has been revived, Scottish Gaelic is mostly fading), and in the distant past, even England itself.

In general, since the rise of large nation-states during the middle ages, the world has been moving steadily towards using fewer and fewer languages. And that process has sped up a lot in the more interconnected world we live in today. There are only about 7,000 languages left in the world, and many of those are spoken by a tiny group of elderly people and will be lost as those people die without passing the language on.