I can only judge by some elderly relations who are pretty non geeky. But rather obviously knew about the EPG, since TVs have had that for years. And the concept of going back in time on that was soon grasped.
You know what I think my knowledge on the subject is out-of-date! It looks like ITV do indeed now support live TV and not just catch-up.
On mine you have to push and hold the search button on the remote for a couple of secs... then the remote then listens to you[1]. There does not appear to be an "always listening for a trigger phrase" option.
[1] Mr Spock, Start Trek style - for those that remember the film.HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.