You don't have to get a GED. It's just one type of high school equivalency, but GED is synonymous with that concept so people don't know there are other options. Pearson likes it that way because they can charge $120 per test, with most of that money going to Pearson.
Pearson doesn't want you to know that, depending on availability, you can also take the HiSET or the TASC battery of tests for half the price or less.
Until a few years ago (before Pearson stepped in) the GED cost $10 to $20 in most places.
EDIT: Not all colleges accept all forms of high school equivalency. And often the HiSET or TASC can be almost as expensive as the GED. Unfortunately it's complicated and you have to do your research. Depending on where you live, you might be screwed either way.
Added context because I didn't expect this to blow up: For decades the GED was dirt cheap because people who need a GED are usually broke. And then magically when education giant Pearson showed up, everybody had to charge ten times as much because one of the easiest ways to get rich in America is to exploit poor people.