Neither. It was 2007 World Cup.
True cricket fans understand that Cricket is a game of talent and some times when equal talents clash, the better team will win on that day. Both in the case of 2003 and 2023, the Australian selectors picked the best possible team and the pitch condition was favourable to them.
Till then, India had won every league and semi-final Cricket match except for a match against Australia in the run up to 2003 world cup final. With the form Sachin, Sourav, Sehwag were on, India had high expectations. But, on that day, Ponting was in a different mindset. He pummelled the Indian bowlers across the park. Javagal Srinath who had announced retirement before the World cup start, was pulled back by Sourav for the World Cup. He took 12 wickets across 10 matches with most of his wickets coming in matches against Netherlands and Sri Lanka. He went wicketless on the final. Such was the bowling performance on the finals that India had no chance chasing 350+ runs playing against the likes of McGrath and Lee.
In 2023, India played perfect till the final day. But if you notice well, most of the matches, India had bowled out the opposition very easily. On the final day, the wicket wasn’t assisting the bowlers in the second half. The dew factor making batting easier helped the Aussies majorly. Along with that, the never give up spirit of Aussies was outshining India’s performance till then.
You know which world cup was pathetic for India? 2007. With humiliating defeats against Bangladesh and Sri Lanka, India were out of the World cup even before reaching Semis, leave alone finals.
2007 world cup will always be remembered for the mockery Bangladesh cricketers made and the humiliating exit for India. What followed was immediate changes in the team, primarily Rahul Dravid losing captaincy.
So in my opinion, as a true Indian cricket fan, the 2007 world cup was the most embarrassing for the Indian cricket team.