Nothing about the sonnet is perfect for the love poem, either. Genre simply provides a way for the reader to look for things that have been done. A form is a useful thing to use. It has history and resonance. It informs you as to the way things have been done in the past.
“Every day he poured his question into her, as you pour water from one vessel into another, and it poured back. Don’t tell me he was painting his mother, lust, etc. There is a moment when the water is not in one vessel nor in the other – what a thirst it was, and he supposed that when the canvas became completely empty he would stop. But women are strong. She knew vessels, she knew water, she knew mortal thirst.”
Anne Carson | “Short Talk on Mona Lisa”