BetterUp Senior Mobile Developer interview questions

In the beginning there are couple of HR calls, then a call with the lead developer, then an online coding session with the same lead developer. After that I got a home assignment to make a mobile app. After that another technical interview with the lead developer talking about my assignment results. Then I was invited to their SF office for a half day interview. They paid for my flight, hotel and food which is good. I felt I did good during the 5 hours interview. I talked to several people in total - HR, PM, UI/UX, Mobile Team Lead again in person. After the trip I got the last call with one of the founders, felt it was a nice talk as well. I had good feelings about this company and the people. So I was pretty surprised getting a rejection letter few days afterwards. Why go through the whole process for that? I asked for a feedback to understand what exactly happened. They gave me no feedback whatsoever giving some bs like "at this point of time we don't provide feedbacks". Not sure if it was due to the fact that I'm currently not in the States or something else.