“Repeaters” is a marketing term. They are routers.
If your devices are mains powered, then they are probably also routers.
it sounds like you are in a house, or are you in an apartment, or have many neighboring wifi’s ?
zigbee, bluetooth, wifi all share share spectrum, so even if your personal network is optimized, does not mean there aren’t other sources of interference.
In my 2 story house, I have bluetooth, zigbee (with hue still on its own hub), zwave, thread, and wifi all working reliably, and while I have neighbor AP’s, they are generally far enough away to not cause problems.
I understand you want something plug and play, but most likely you will only create more interference/issues by adding more networks, instead of minimizing networks.
Mostly being the word that would drop e.g. Aqara off the network.
If you have several hubs, the devices on each hub won’t be able to route for each other, leading you to barely having any routers per network.
It sounds like you are digging your own grave. I have 60+ zigbee devices running smooth on just the one coordinator and ZHA.
I would just reiterate that this sounds like an environmental issue rather than an inherent issue with a zigbee coordinator and ZHA.
I’ve been running a sonoff dongle-e with ZHA for several years with rarely ever an issue. Months can pass without me having to touch anything.
How would you explain that an Ikea tradfri button has fallen out of the network being 1.5 m away from the coordinator?
Or that the 3 plugged out of 7 Ikea routers have suddenly left the building?
As much as I want to believe experience of people who manage to have a stable network I am drawing conclusions that even the sonof coordinator failing in my case.