Do you think eventually the whole world will speak English with an American accent?

No. Accents are very regional.

Brooklyn, Boston, Long Island, South, Deep South, Texas, Midwest, Upper Midwest, Cajun, are a few examples of regional accents.

A great example is Latin. It didn't die out, People began to speak in what was called Vulgar Latin. Vulgar Latin eventually morphed into Italian, French, Spanish, Romanian, Portuguese.

Another example is Chinese. Most Chinese can read anything written in Chinese, but someone speaking the Wu dialect may not understand someone speaking Mandarin.

Nah anyway not all Americans even have the same accents and i like other foreign accents anyway

I think the chances of that happening have rapidly diminished over the past half year!