Up until the switch I’ve had a patchwork system consisting of Alexa, Smart Life (app), Smart Things, and a lot of digital duct tape.
Having both 1) a central "command center" and 2) Zigbee/Z-Wave capabilities (requires a dongle) suddenly opens up so much more opportunities than WiFi components alone. EG I've attached door sensors to my garage doors to trigger lights and notify my dumbass when I leave the garage open at night.
Plus, I'm no longer locked into one brand's ecosystem and can keep my patchwork hardware setup.
Big fan here, strongly recommended.
Note: I have no association with any smart home brand/equipment nor home assistant… though I'd consider being associated with HA.