How bad are Aqara devices? Do I need to get rid of them?

Before blaming an end device, it’s brand, it’s advisable to have a reliable zigbee mesh, which can be a PITA, depending on a few criteria.

It might help to have a look at this from a fellow HA user: Zigbee network optimization: a how-to guide for avoiding radio frequency interference + adding Zigbee Router devices (repeaters/extenders) to get a stable Zigbee network mesh with best possible range and coverage by fully utilizing Zigbee mesh networking