True! It's a pain to clean and access the back with sliding doors and sometimes taking a picture can be quite challenging but I still prefer sliding because 95% of the time I need to do something else than that.
With sliding doors you can easily access each side without exposing the other. This is good for your animal safety (your Bearded Dragon won't fall or get stuck on the other side) and less prone to accidents (the doors don't slide on their own and a swing door can be open if something heavy applies enough force to it, like a basking log falling on the door).
Sliding doors are also more energy efficient because you only open what you need and they also allow you to
safelly place a grid if you need to cool down an enclosure.
Last but not least, they will fit any place and swing doors won't.