Disclaimer: I have two Roku TVs
In general, it's usually not advisable to combine multiple functions into a single device. There's two reasons. First, if one function breaks, it requires replacing a device that still functions in other ways. So if a printer/fax/copier suddenly loses its ability to fax, you have to replace the device even though the other functions still work. So it's wasteful. The other reason is technology devices continue to improve. You can buy a quality TV that will last for many years, and use an external device as your streaming source. That way as the tech improves, you can replace an inexpensive player and continue to use the far more expensive display.
While it can be cheaper to buy an all-in-one, in the long run it could cost more if you want/need to update something. While almost every TV I own now has some sort of smart streaming function, I don't use any of them in that way, other than the two Roku TVs. And I only bought them for that use because they were inexpensive. My two main large screen TVs have internal apps, and I don't use any of them. I use both Roku players and the Nvidia Shield.
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