Smart TVs have a bad record of having their interfaces/applications updated.
Actually, the main apps I use on my Samsung Smart TV have been updated reasonably well. (My Smart TV has the gesture control, but not the voice. I turned it off in the service menu. It's a pain to use and turns itself back on if you turn it off from the regular menu).
Having said that, I'm not happy with the "smart" features of the TV (compared to Roku). I've replaced the other (dumb) TV with a Roku TV, and the UI is just tons better than the Samsung, and surprisingly nicer than adding a Roku to an dumb TV. Until something better comes along, the only TV I'd recommend is a Roku TV.