Pro-tip: use zigbee2mqtt's groups for targeting multiple lights (but I'm guessing OP is using ZHA).

I've also used HA for quite a few years, and I have several hundreds of devices. I just (this week) decided to move Mosquitto and z2m out of HA to LXC containers in Proxmox (where HA is already running) and it was very easy. Now I don't have to restart the entire world whenever I have to restart HA (usually updates).

Next is to move Node-Red out to its own container. I already do not use HA's automations because they are very poor compared to Node-Red, and I'm starting to change all flows to use MQTT directly instead of passing through HA.

So in the end HA will be relegated to run non-MQTT integrations and dashboarding and not be a single point of failure.