As soon as you do you'll get nagged for software updates, you'll get told the privacy policy or the terms of service have changed (which you have to acknowledge) and apps for things like Youtube and Netflix tend to be inferior to those in boxes (eg Roku, AppleTV).
I buy my TV to be a dumb screen. Then I plug a Roku into it. If at some point I decide the Roku isn't working I throw it away and get something else. Worst case I'm out $120.
Non-smart TVs basically don't exist anymore (Sceptre is the only brand I can find). You can usually get a smart TV and keep it off the internet, but I've seen horror stories of some TVs not working at all until being "updated" after unboxing.
A similar pet peeve of mine is that the huge infotainment screens on modern cars cannot be turned off the majority of the time. Only in the VW Golf I rented did it actually have a way to shut the whole thing down.
I think a dumb screen option will always be available because it's always going to be a value player in a world of Sony and Samsungs. The question is will the screen be a nice enough panel.
But I could have saved a lot of money by going with a conventional Smart TV, and it would have been easier to shop for it. Commercial displays aren't hanging on the wall at your local Best Buy, although they might be hanging on the wall at your local bar, restaurant, bank, etc.
It is not possible to buy a high-end panel without it anymore.
AS long as you just use it as a dumb screen, physically disconnected from the network, it'll keep doing it's job for year and years.
My TV is a Smart TV. I've never use that part of it. In fact, it came with a second remote control for managing the Smart features and I've never even put batteries in it let alone given the panel network access.
It's been happily humming along in dumb mode for about 4 years I think. Just plug a cheap accessory of your choice in (Fire TV, Chromecast, Roku, self built HTPC etc) and enjoy!
Of all the television sets I have owned since 1985, the native tuner included inside the device has been used maybe 2% of the time. The only advantage I have ever seen from buying a display screen as a television set is that it comes with speakers loud enough to hear from across a large room, and has as many as six different input ports. None of the screens I now own currently decode their own NTSC/ATSC/QAM signals.
My first "smart" TV was also my last, because LG made it obsolete within months of me buying it. Now it also functions only as a dumb screen, and is not allowed on my home network. Never again.
You don't need a smart television now. You don't even need a television. You need a monitor with HDMI inputs and speakers.
And if you want a DisplayPort input in lieu of one of the HDMI sockets, that seems to add at least $30 to an otherwise identical monitor, even though DisplayPort is royalty-free. There does seem to be an attempt to segment the market to charge more for displays connected to a computer than for displays connected to a home entertainment appliance.
At larger sizes, I think the assumption is that if you don't have a TV tuner, you're attaching it to a computer, and if you do, you're not. And that breaks down at smaller sizes, where resolution and pixel pitch become an issue for computing, but less so for consoles and DVD players.
I haven't done much digging on this, since 40" is plenty for the longest line-of-sight possible in my house.
I'm using an NEC E-series 55" commercial display as my TV and gaming monitor. It's not a great TV, but it is solid and it's way better than the one it replaced.
If it's never connected to the network....
The Chromecast could be discontinued tomorrow, but it only cost £30, so I'll just replace it with whatever. Relying on your expensive TV's probably terrible and badly supported software is madness, but it's what most people seem happy to do. It's getting harder and harder to buy TVs that are not smart, and I find it maddening.
I take the same approach with Speakers.