Chelsea clearly was the stronger team. It was the last season result that made Chelsea play the conference league. The current team is built up for Champions league.
Chelsea as a team kept improving throughout the season both in the premier league and conference cup. Their premier league start was not as spectacular. They were playing draws with Manchester United and losing against Fulham. Even in the Quarterfinals of Conference League, they lost a leg against a much weaker team but won on aggregate. But reaching to finals, they have improved much, qualifying for champions league through premier league and winning the conference cup to have a title on their name.
This is what Chelsea deserved after they played quite well this season, more precisely the rapid improvement that was seen after the Chelsea team was really better.
Chelsea's victory over Real Betis in the final match also showed how the mentality of Chelsea players was much better so that they could turn things around in the second half.