To update your PS Vita:

It is the primary gateway for "downgrading" via tools like Modoru. 💡 The Gateway to Homebrew

It serves as the baseline for the modern Vita experience.

If you want a plug-and-play experience without modifying your console:

The official "story" from Sony was the usual—"system software update improves system performance"—which the community affectionately translated as "more stability". In reality, the update primarily targeted the system's WebKit, but it was a rare case where Sony didn't actually block the most popular exploits of the time. The Legend of the 3.73 Update For the modding community, 3.73 became a unique crossroads: