Is it unusual to consistently fail on sites interviews for years

I seem to have enough skill to make it to a on-site, and even had some spectacular interviews performances by using some esoteric data structures: Trie and Union Find. Still, I will have one mediocre interview where I look mediocre or just bad that renders the other 5 interviews useless. It’s like I have to look like a 10x developer for 5 interviews in a row while my interviewer looks for a tiny reason to disqualify me. The company recruiter will say the interviewer is looking to see how I think, but often interviewers will fail me for the code not compiling that I wrote on a white board. I had interviews where I write the best solution, and the interviewer will fail me because I missed a opportunity to optimize the algorithm for a edge case. I have seen interviewers add extra requirements to try and trick me at the end of a long on-site. I understand why big companies try not to give feedback because the reasons that interviewers fail candidates sound so absurd that one can only imagine if being same race/gender as the interviewer would have change the outcome. Does anyone find the current interviewing landscape ridiculous? After someone spends the sufficient amount of time on leetcode, is it just a lottery for programmers who are not competitive programming. I have read or used the CLR, Cracking the Coding interview, leetcode, interview.io, pramp, 1 on 1 coaching from Google engineers. Do I have to devote my free time to competitive coding competitions over side projects. What does it take to pass on site at a name brand tech company?