Niantic interview questions

The recruiter approached me to apply for the position based in London within their research team. After several successful coding and technical interview rounds, I was happy to advance to the final behavioural round. Before the last interview, Niantic even approached my current employer for a reference in a video call. I was happy with the last round. However, it took almost three months and six rounds to determine that I was not the right candidate because of other better candidates. The last two rounds were unnecessary, in my opinion. Speaking to the line manager for a reference wasted his time and exposed me to the risk of losing my current position. I am sorry, but I cannot understand why a company would do that with someone. It is entirely unethical, in my opinion. I feel terribly sad about the whole experience. I suggest cautiously approaching Niantic Research (London) due to the lack of ethics and HR policies.