“I like to choose topics of discussion that I personally am interested in as this helps me to be really motivated when listening to what the students say. Are there any downsides to this?”
Don’t fixate on your pet interests when choosing the types of topic you get students to talk about.
Likewise, don’t assume that just because you don’t find something interesting that your students won’t either.
Choose topics based on their interests.
I once conducted a survey of my students’ previous learning experiences. The comments in blue below come from this survey.
I don’t want to discuss things that I would find hard even in my own language, so even if you think that you have some great discussion ideas which you yourself would like to discuss, your students may not agree with you. You have to respect them and not force your discussion on them.
In any case, having interesting topics to discuss in class is not enough:
I had one English teacher that put a lot of effort in making not boring lessons. But she did not teach me anything, because she required too little effort from us and did not pay enough attention to our errors and difficulties.
This was mirrored in another comment:
I discussed world news and important social issues, something about psychic and paranormal activities, but during the lessons we had no opportunity to practice scenes from everyday life to improve our current lexicon.
Students have to perceive that there is some value to your lesson. They are not there solely to be entertained – though being entertained is an important element.