Seismic interview questions

After 8 rounds of positive interviews and spending around 3-4 weeks in the interview process, they didn't offer! I was initially pitched for an SDE 2 role. First, the screening round, and then scheduled for the main loop of 3 rounds. I noticed the invites for interviews changed from SDE2 to Senior Software Engineer 2. I thought either that was a mistake from their end or I was upgraded! During the first interview, they mentioned that many of their hires don't know their stack. I completed these 3 as it was for a Backend role, they said, since I had full-stack experience, they would want to take one more round for frontend. So went on with the fifth round. The recruiter said they would want me to take two leadership interviews as well with Senior VPs. Okay went on with the 6th and 7th rounds. The recruiter came up and said he was talking to one of their new VPs, and he was interested in having one more discussion with him as well. Okay 8th round. Well, everything went well so far, they seemed positive, showing me the office and talking to so many folks from the company. It was obvious I would receive the offer. But I didn't. The recruiter emailed me saying they enjoyed the discussions with me, but they need someone more experienced in their tech stack! Like, why would you waste leadership and my time? This is something you could have understood after 5 tech rounds! (even that's too much!) This indecisiveness from the company costed my efforts and time. It was horrible to face something like this. In the face of that, they wanted me to take more 3-4 interviews at some other team because they thought I had potential with this company, of course not!