#3 The Great Khali

The Great Khali served WWE well during the late 2000s, and did enough to increase the international viewership for the company.
As soon as the decade ended, so did Khali's popularity and impact on the main roster, as WWE made him more of a joke rather than a real monster because of the existence of Kane and the Big Show, who were already playing the main monster roles.
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Khali has been used a lot in Royal Rumble matches by the WWE, but has never been impressive enough to seem like a real threat even when effecting a number of eliminations. His time is up now, and he should hang up his boots rather than return for another Royal Rumble event.
Khali last returned for the Greatest Royal Rumble event in Saudi Arabia where he entered at Number 45 and was eliminated by Braun Strowman and Bobby Lashley in about thirty seconds. This showed that he was mainly included to push the position of Strowman and Lashley further as the new monsters in WWE.
Returning for another Royal Rumble event won’t do much for the superstar or the company, and would simply deprive a deserving superstar a spot in the match.