This does reduce a young girl to property in essence which is kinda disturbing. But let’s make sure we look at this in context. And this context requires more than just a few verses before and after.
First let’s note the 6 year time factor.
A person buys a girl as a slave. This does not give the master the right to have free sexual relations with the girl.
If within six years the person marries or has sexual relations with her, she is no longer a slave. If after the six years, the salve and master have not had sexual relations, the father may purchase her back to be his daughter again. She has to be a virgin.
It is not God condoning sexual slavery. He speaks against sexual misconduct in so many other places in the Bible that this one verse cannot trump the others.