I stayed in a backpackers hostel in Singapore a month ago and was bitten by bedbugs. Annoying little buggers.
Bedbugs are hard to get rid of particularly when you have thick matresses to have plenty of hiding places.
In tropics you don't need matress for warmth but for comfort.
I think you can do
Hammocks are comfortable and you dont need matress with them if it is warm enough.
This system would kind of similar but not the shape of hammock. Some kind of rectangular fabric like a tarp with holes for attaching into the hooks on the frame.
So hotels and hostels would have metal frames where you attach these sleeper tarps from each corner and adjust the tension according your preference.
You would be able to hire one from reception or use your own.
No need for pillows either as you would partly sink into the tarp and have comfortable sleep without pressure points.
These sleeper tarps would be lightweight and easy to wash.
Also they would have small holes to let air through for cooler sleeping.
These tarps could be easily washed just like any sheets and would be bug free.