Maybe - I would agree with you when it comes to things like Alexa and all that rubbish, they are just gadgets but Hive is really useful. The ability to programme different temperatures for as many time slots (and days) as you need, zones (if you're CH system supports it), setting it to come on remotely, switching it off when you've gone on holiday and forgotten! It makes you much more aware of the temp of your house and how long the heating is on for, ultimately saving you shed loads.
Obv it's not for everyone but I wouldn't be without it now....
Nice. How do you know if your CH system will support zones?
Good question - I'm no plumber so someone may be able to give a clearer explanation but you should be looking for at least 2 of these zone valves wherever your CH pipes disseminate from https://goo.gl/images/QsCiri and stop taps beyond them on the pipework. Hope that helps.