I use slides when I teach because:
It forces me to prepare for class in advance. (This is usually not a problem for me, but I had a professor in undergrad who only wrote on the board because he didn't have a lesson plan or anything prepared for the day. I vowed to never ever teach like that!)
I have time to articulate my thoughts on my slides.
The information that I want the students to know is on the slides. That means that EVEN IF I was lecturing too fast or a student couldn't take notes fast enough or the student couldn't read my handwriting or a student couldn't come to class, it doesn't matter. Because all the information is on the slides and I provide them with digital copies.
I get way more joke opportunities with slides and I can keep the students engaged.