Had a phone screen, two rounds of interviews (each with two individuals), and completed a written assignment. Received an impersonal rejection email and was turned down when I asked for feedback on my application

Process was: brief phone screening with HR, 1 hour in-depth interview, uncompensated analysis assignment, second 1-hour in-depth interview. The questions in the longer form interviews were very good and demonstrated a clear sense of the culture. Generally, I believed communication and interviews to be informing and interactive. But the assignment that was given was quite elaborate and went completely uncompensated. Additionally, when I was declined to move forward after being so far into the interview process, I simply got a copy-paste email from HR saying that I "did not possess the skills or background needed for the position". One would think that this was truly the case, it would be decided earlier on. After a screening I understand that this response can be used. But after dedicating so much time and sharing my knowledge (for free), this sloppy of a rejection is extremely disrespectful. It was a disheartening experience and a waste of my time.