Sequoia Disappointing Lengthy Process interview questions

The challenging part of this interview was the number of interviews they required, I had to go to their offices 5 times. I met with various levels of people. This was for an IC role so unclear on why there was a need for the number of interviews that I had. I was a bit frustrated to have to go through so many interviews to end up with no offer, but interviewing is always good practice. Some feedback would have been appreciated but was not given.