Many countries, including Israel where I live, have long had matriculation tests at the end of high school. Passing them is considered far more important than the high-school graduation diploma, which is given separately.

You can sign up to take the matriculation tests even if you are not in high school. This option is generally intended for drop-outs who are catching up later in life, but you can do it as a teenager too.

After passing the tests, no one cares about your actual high-school grades.