Cloud services are okay as a bonus/optional thing.
But the key feature is local control. I have 250 smart devices, all of them are locally integrated via home assistant
If the manufacturers go out of business or if the internet is offline nothing changes for me.
I use home assistant for local integration. I don't see it going mainstream but for those with a tech background it's amazingly powerful.
150 of my devices are high end lutron ra3 switches/keypads. Prior to getting them, I would have to turn off 100 light switches every night. Huge pain.
I've automated everything. shades, interior lighting, exterior lighting, pool lights, ceiling fans, whole house fan, pool slides, pool features, etc, etc
Expensive and time consuming but when done well it's awesome result.