FINN Manager interview questions

The CEO of FINN reached out to me on LinkedIn. The interview process started out very positive. I really enjoyed the person and the interview felt conversational. It is clear FINN wants to get ideas out of candidates during the interview process, use these ideas, and then not compensate the interviewee for what is an extremely long, time-consuming, and involved process. After my first interview, FINN asked for my college transcript. Prior to the second interview I was provided with a detailed pitch deck to review (which is fine, but during this interview process you are expect to become very familiar with their business model and speak to how you implement improvements). After making it past the second interview I had to complete an online logic test (Bryq) which was extremely difficult and irrelevant for the position. I also had to complete a lengthy case study with 3 parts (data interpretation, a slide deck, and word document) - this took me well over 20 hours (they said candidates typically take 5-10 hours, no way someone could've completed this is 5 hours). After the third interview (90 minutes of presenting the case study) with one of the C execs and other interviewer I was exhausted. I put so much effort into the process, gave them extremely creative ideas and feedback that they will use, to ultimately find out they were continuing the process with other candidates. They did provide feedback, but it is clear they are not looking to invest the time into training talent. Advice - hire off potential and motivation. I feel used and upset by how this interview process ended. Be warned you are expected to INVEST and GIVE a lot in this interview process. (Also, because they are in Germany expect interviews scheduled for 8am)