It's got some sharp edges - every time I've done a major auto-update it's broken something critical. You can run it alongside other controllers like the Hue Bridge, which is nice to have as a backup (since 90% of what most people connect is smart lighting). Probably the most useful simple automation I have is an motion activated dim light in the bathroom at night, but that's using Hue.
Then look at ESPHome, which is an ecosystem for making your own DIY sensors and controllers that can feed into HA. For example we have a Sensirion air quality sensor that triggers a smart switch connected to a fan if the particulate level gets high when cooking. You can go a very long way with on/off to control non-smart devices, and your sensors don't need to be particularly accurate (like absolute PM2.5) as long as the conditon you trigger on is repeatable.
The only thing to think about is what hardware ecosystem makes sense for you. For example there's at least four different competing standards for connectivity (WiFi, Zigbee, Z-Wave, Matter/Thread, etc). So getting a Zigbee dongle isn't a bad idea because then you can connect any IKEA or Hue device (among others).
AppDaemon[0] runs alongside it and is more "real" Python, it mostly just responds to events sent to it.
NodeRED has a direct integration and is (in my experience) best for complex state machines as you can easily debug them and actually see the logic work.
They also have a REST API to trigger things and a Websocket API if you need more real-time stuff (subscribing to events instead of querying states)
Then there is just straight up MQTT, where you need to do it all yourself.
What HA shines is that it tends to have ready-made community integrations with _everything_. And enough users for each that if something breaks, people will notice and it'll be fixed promptly.
The hue motion sensors pay for themselves pretty quickly.
The rest is zigbee and zwave switches and sensors. You can get cheap ones from ikea. You can get nicer ones from Zooz. I like Apollo for air quality sensors. The humidifier is the German brand Ventura. Zero maintenance. But it’s not smart so I got a power outlet that reports power usage. When it runs out of water the humidifier shuts off and the power goes to zero, so I have an automation that detects that and sends a message via the HA app.
Living in California and having fans move air around from cool rooms to warmer rooms has cut our AC bill significantly as a dc fan is a fraction of power consumption of a whole house AC. And also co2 levels stay much lower. Last week I set up my window fan to blow air in whenever it’s cooler outside then inside.