You can't leave a group text on your Android phone, but you can still mute or delete the thread in your Messages app.
One reason people prefer group chats in Apple's iMessage or RCS texting is the extra control and security these platforms provide. If everyone in your group is using iPhones, or if you're on Android ...
Previously, US carriers were slow to warm up to the RCS messaging protocol. While iPhone owners have had iMessages for years, Android users often relied on third-party messaging apps like WhatsApp.