Being part of a World Cup-winning squad in itself is a great achievement. Getting selected in the squad means that you were capable of making the best available XI of your country.
Having a world champion medal around your shoulders, no matter how much you contributed on the field in the tournament, would still remain an enviable feat to attain that every player desires for throughout their careers.
Interestingly, there have been a few cricketers who are world champions, but they hadn’t even made their debuts in that format for their country. This is one of the most rare list that you will come across.
3 players who became world champions before even making their debut in that format:

Piyush Chawla
Yes, leg-spinner Piyush Chawla is one of the few players in the Indian team who was part of both the T20 WC 2007 and ODI World Cup 2011 winning squads. Chawla hadn’t made his T20I debut when the T20 WC 2007 and was picked on his potential, but he didn’t get to play a single match in that tournament, but the leg-spinner is a T20 World Cup winner. This way Chawla was a T20 World Cup winner without a single T20I match under his belt.
Chawla made his T20I debut three years after that WC triumph, making it one of the interesting stories of his career.
Josh Inglis
Australia recently won the World Test Championship 2023, defeating India in the final by 207 runs at The Oval. Alex Carey played as the keeper for Australia and the left-hander has been their first-choice keeper since Tim Paine stepped away from Test cricket in 2021.
Carey has not missed a single Test since then and Josh Inglis has remained his backup throughout. As he was in the WTC Final. Uncapped at Test cricket, Inglis was in the squad and is now a World Test Champion.
Sunil Valson
A left-arm pacer from Andhra Pradesh who played domestic cricket for Delhi and Railways, Sunil Valson was part of India’s 1983 World Cup winning squad. He hadn’t made his ODI debut till then and warmed the bench throughout the tournament. What’s shocking is that Sunil Valson never got to play for India in his career as he was dropped after the World Cup win.