My previous TV has a Roku stock (earlier gen) that works fine, but drags ass sometimes. I thought about getting the highest-end Roku for about $100, but instead I got a larger TV with newer Roku built in, and for a little over $200. :^)
My one TV, a Vizio is about 5 years old the Netflix app built in no longer works because Netflix isnt supporting TVs and DVD players that old. The plug in Chromecast can access Netflix and Chromecast plus Google keeps updating it as things change. Cheap to get new $39 device when it’s no longer supported than buy new Tv