Yes, there were people who were anti-slavery for moral reasons.

Let’s not forget that there were plenty of people who thought that Africans were inferior who wanted slavery ended for economic reasons.

A slaveowner would rent out his slaves to do work for less money than any free man. Many slaveowners would bring skilled workers over from Europe and pay them for their jobs, and also to train some slaves. After the master carpenter moved on, the slaveowner had a dozen carpenters on his plantation. When they weren’t working for him, he’d rent them out. That meant that it was impossible for any local carpenters to earn a living.