It was the second successive World Cup where they missed out on a semi-final spot by finishing in fifth place in the 10-nation table.
The 2019 debacle led to the end of Arthur's first spell as head coach.
"Look, I'll just go back to the Peak District in Derbyshire, I'll be really happy and that'll be okay," said Arthur after overseeing a campaign which brought four wins and five losses, including a defeat to Afghanistan.
Arthur did not sever his ties with Derbyshire and only joined up with the Pakistan team once the English county season was over.
That was an arrangement severely criticised by some former Pakistan players who described Arthur's job as "coaching on Zoom".
Arthur admitted that 1992 champions Pakistan simply did not play well enough.
"We finished fifth, and fifth is where we deserve to finish with the cricket that we've played over the last six weeks," said Arthur.
"Inconsistency, unfortunately, doesn't breed success. But that is no excuse at all."
He added: "I came in to do this directive job, obviously in conjunction with Derbyshire because I care a hell of a lot for that dressing room. Pakistan cricket is very close to my heart."
With Pakistan out of the race for the last four, New Zealand will now meet undefeated India in the first semi-final in Mumbai on November 15.
Australia face South Africa in the second semi-final in Kolkata a day later.
"I really believe the best four teams in the competition are now playing the semi-finals," admitted Arthur.
Arthur also backed under-fire skipper Babar Azam to stay in the role.
He also insisted that the injury-enforced absence of key strike bowler Naseem Shah on the eve of the World Cup was a blow from which they never recovered.
"Babar is very, very close to me," said Arthur. "He's a young guy that needs to be taken on the journey. He needs to be shown the ropes. He's still learning all the time and is growing."
"What we've continually tried to push is that we're behind the eight ball. Our game needs to go to another level. I think we missed Naseem Shah. But if you get Naseem Shah, our bowling attack's good."
Runs also proved hard to come by on a regular basis with not one Pakistan batsman making it into the top 10 run makers at the tournament.
"Batting-wise, we have to become a 330-350 team. I don't think we've done that consistently enough. We do that when Fakhar Zaman comes off and we can't just be relying on one-on-one players."
Arthur said he was already planning for the three-Test tour of Australia starting next month.
Pakistan have lost 14 Tests on the trot in Australia and their last win was in 1995.
