Accenture Senior Embedded Software Engineer interview questions

First, there was a simple online coding task with common questions. After that, I was invited to an online technical interview. The meeting was scheduled for 1 hour and 30 minutes, but HR mentioned that it usually lasts around 1 hour. However, the interview ended up lasting 2 hours, which is quite long for anyone. On top of that, I noticed that one of the interviewers had less experience than I do, which I consider a bit of a red flag for an interview. Two days later, I received a rejection email. I didn’t get any feedback, which was disappointing. If it was already clear that I wasn’t suitable for the position, then why did they take two hours of my time?