Weekend variety block that once topped South Korean ratings before bowing out in 2017

This clue leads to Good Sunday. The sections below explain what it refers to, why it matches the clue, and why it may be appearing in the current trend cycle.

Good Sunday was a South Korean reality-variety show shown on the SBS network, which competes directly against MBC's Sunday Night and KBS2's Happy Sunday line-up. The program has suffered from the competition of Happy Sunday and Sunday Night but reached its way to #1 on the Top 20 Charts every Sunday. Good Sunday consists of a line-up of "corner programs", or segments, which air within the program. The program ended on March 19, 2017, opting for individual programs divided into two parts for inserting commercials.

Background summary sourced from Wikipedia (CC BY-SA). View source

The clue points to a South Korean TV program that aired on Sundays and consistently ranked #1 in viewership charts. "Weekend variety block" signals a Sunday lineup, and "topped...before bowing out in 2017" matches the show’s ratings success and its end date of March 19, 2017. Good Sunday was SBS’s flagship reality-variety umbrella show, broadcasting multiple short segments back-to-back every Sunday evening until the network split it into separate programs to insert commercials.