Why do men let go of the “perfect girlfriend”?

For context, my 24M BF and I 24F just broke up two weeks ago. I initiated it because I felt like he was not acting the same and he told me he felt like he lost the connection with me.

He also told me that I was the perfect girlfriend, and was everything he ever wanted and he genuinely doesn’t know why he lost feelings for me. One of the last things he said was , “if you give 10% of what you gave me to some other guy one day, he will be the luckiest man ever.”

The next day I called him to see if there was any chance for us to be together again and he said no. That was two weeks ago and we haven’t spoken since. He’s always been adamant that I was everything he’s ever wanted in a partner, and he even told a friend this who shared it with me after the breakup too.

Just feel very confused :(