Your time
How much of your precious TIME does it take to operate each system properly?
Suction cleaners and robotic cleaners are best described as semi-automatic cleaning systems. Once YOU have unpacked them from their hiding place, they need to be positioned in the pool and either connected to a suction point (suction cleaners) or connected to a power point (robotic cleaners). To unpack, install, and then remove your semiautomatic cleaning system will take at least 20 minutes of your precious TIME on each occasion. During summer, when you're using your pool the most, this can be a daily task.
In-floor cleaning systems are the only truly automatic cleaning systems, because they are permanently installed, and operate automatically on a daily basis.