Smart technology will save you money in addition to being good for the environment by saving energy.
Being able to see your energy usage go up as you use an appliance gives you a greater understanding of how you use your energy and spend your money. Its amazing to see the huge increase a kettle makes over the normal day-to-day running of your house (or background radiation as we like to call it) but a kettle is only on for a short time.
If you have solar panels a smart meter also gives you a chance to play the 'oh the sun is shining - quick what can I put on?' game where you run frantically around the house gathering a wash to put on, or plates and cups to fill the dishwasher.
Being able to adjust your heating schedule from your phone/tablet is really useful and easier than standing at the controller. This means you can alter your heating for the seasons or a particularly cold spell without putting it off because you dread dealing with the controller. It also means that if you are out you can also control your heating for those unexpected invites (I wish - we're still in Lockdown 3)
Remotely turning lights and appliances on and off. We haven't seen the need for these yet but when the kids were all living here these would have been brilliant.