I’m planning to build several WiFi connected devices for home automation: an AC remote control and air quality sensors. These devices would send data and be controlled through a local server. I’m considering two approaches: running custom software on a server PC (hardware to be determined) or integrating with Home Assistant’s protocols and purchasing their hardware. Would using Home Assistant be excessive for this use case?


Most WiFi devices these days are cloud-based, at least on the American market.
If you can find a Zigbee or Z-Wave (or the up-and-coming Thread), those only work locally. The only way to get remote control is to expose HomeAssistant (or a similar hub) to the internet - usually using a VPN from your remote devices into your network.
It’s a bit more upfront work, but no one can track your devices, they’re off grid/much harder to hack remotely, etc.