I've replaced all of HA with just some Python interacting with an MQTT server. I just script all the automation and don't have to care about the other 90% of what HomeAssistant brings to the table.

Not for everyone obviously but it's simple and works well.

Have you looked into AppDaemon or Pyscript, both provide a Python interface to HA.

They let you use HA's massive library of supported devices, but you don't need to bother with their YAML "programming" horrorshow.

I haven't because what's described didn't really suit my needs. I can run my own daemon that will handle the integration with MQTT, and that's all I needed.

I haven't found anything better. I want to try Hubitat and OpenHab at some point, maybe they'll be better.

All the community is behind HA though, so it has the most integrations.

Consider leveraging the HA ecosystem of integrations, but for automations add Node Red. There is a well maintained WS node to HA that lets you call any service/action in HA and listen for events or device state changes. https://flows.nodered.org/node/node-red-contrib-home-assista... Along with everything else NR provides like MQTT pub/sub, only limit is imagination and time. I've been doing this for years. Another moving piece I know, but it has been bullet proof for me