There are also enormous social pressures to stay in abusive relationships: people feel free to tell you you should stay in a relationship, that it can be fixed, etc. Very few people are willing to tell someone they should leave a relationship. So, what you hear is everyone thinks it should be fixed rather than ended.

There are many practical difficulties in ending a relationship too: financial, legal.

There are also many things in pop culture and media that can encourage it: normalisation of what are actually controlling behaviours, for example. The even "when you are right you are wrong" trope is just one common version of this.