Gujarat Titans had the best players and they were the heavy favorites with the best bowlers in Rashid Khan and Mohammed Shami, the inform batsman in Shubman Gill while Chennai Super Kings was winning because of their tactical game plans and the genius of MSD, promoting Ajinkya Rahane as a pinch hitter along with Shivam Dube and grooming the youngster Maheesh Theekshana.
Just compare the two squads and you can see that Gujarat Titans were much stronger (at least on paper). Out of the 12 players in Gujarat playing XI (including the impact substitute), 7 were regular internationals - Shubman Gill, Hardik Pandya, Rashid Khan, David Miller, Josh Little, Noor Ahmad and Mohammed Shami. On the other hand, Chennai squad had only 4 regulars - Devon Conway, Ravindra Jadeja, Moeen Ali and Maheesh Theekshana. In the end, Mahendra Singh Dhoni was able to lead Chennai Super Kings to a victory, despite majority of the CSK players being inexperienced.
Yes, Shubman Gill, Hardik Pandya, Rashid Khan, David Miller and Mohammed Shami are some of the best players in this team as well as in this tournament. Compared to them, CSK looked very weak. But the team had confident because of Mahendra Singh Dhani. When the 2nd innings started CSK was playing confidently and they scored according to their need. But the cricket world realized that CSK was under a lot of pressure in the end but having much pressure CSK won the final match. Although Devon Conway was considered player of the match after CSK's win but Shubman Gill was the player of the series.