Confused on K-ETA requirement for U.S. citizens

Hello, We are headed to South Korea for a week in April. I read online that the K-ETA exemption has been extended through Dec. 31, 2025.
Does this mean I just show our passport when we arrive?

There is still an option to apply for the K-ETA for "other benefits such as not having to submit an arrival card."

Can someone confirm whether or not I need a K-ETA card and/or is there a benefit in obtaining one if it's not required?