The specs and quality of the panel, backlighting (if applicable), and image processing. These days, the few "dumb" TVs that are still sold are either cheap and bad or are designed for signage use and aren't well suited for TV/movies/games relative to their mass-market smart cousins.
A smart TV used as a dumb TV alongside a quality streaming box (Apple TV or Nvidia Shield TV) or console gets you the best overall experience.
To each their own, but the good ones last a long time even if they’re a little pricey. As an example, the original Apple TV 4K which was released in 2017 is still quite serviceable and continues to receive updates even now. A unit purchased in 2017 for $179 will have worked out to $18/year assuming they’re still using it in 2027.
You get a much cheaper TV. The folks who manufacture the TV expect to make a certain amount of revenue from your data, so they price this into the cost of the TV. This saves you from having to spend more money on a commercial display that often has a worse panel.
There's a variety of reasons, but many of us don't want any of the "smartness" and all of the stupidity that comes with "Smart TV's" these days, but don't really have comparable "dumb" options at similar or cheaper price points. The Telemetry (ACR), unremovable copilot app getting added to LG TV's, or all the Ad's Samsung are cramming into their "smart" garbage are three prime examples, but certainly not the only reasons I hate smart TV's (or really any device marketed as "smart") these days.
Most importantly though, can you even get non-smart TV's these days that aren't super budget items? To my knowledge that's pretty much not a thing anymore (yes there are presentation displays and large format monitors, but that gets into the weeds fast about feature/panel/spec differences, not to mention price differences)
Several Sony models are also very good, being built with Samsung panels and their own in-house image processing which is some of the best in the industry. Their TVs run Android and support offline firmware updates, too, which is why they're usually what I buy.
One answer is that all you wanted was bright, sixty inch monitor for your living room, into which you could plug your HDMI sources, but all you could get (subject to various other constraints: price, quality, availability, non-smart features you do care about, ...) was a smart TV, whose "smart" features you explicitly don't want.
You don't have to use every feature of something for it to make sense. I have a "dumb" TV. It has built-in speakers, but I don't use those. Volume is set to minimum. My streaming box connects to decent bookshelf speakers.
I don't use the Smart features and instead use a $30 Amazon Fire TV stick (for streaming services) and a Raspberry Pi (for torrents).
This has the major advantage that if the streaming hardware is ever obsoleted for any reason (ie, Netflix decides my TV is too old to support a compression codec they want to switch to), I only have to buy a new media player for $30 and not a whole new TV.
The point is I don’t want my TV, my refrigerator, my toaster, my dishwasher, or my washing machine to be “smart” or to have any AI or internet connectivity.
These all have a very simple job to do, and there’s absolutely zero value-add to the smart edge software nonsense.
The ability to own a TV at all, since even the cheaper sets now have this nonsense built right in. Loosely I think the idea is to subsidize the cost of the hardware with the marketing deals, but I don't actually know.
What you do is you should never do is connect your tv to the internet. You connect something you control and can turn off if you don't like it, like say a google youtube tv dongle, or apple tv. You can unplug them if you don't like them.
If you connect your tv to wifi, it can spy on you all the time. It can upload info on what you watch even if you used an external google tv puck to watch tv. It can see what you type on the screen if say you use it for say a monitor. There are reports of people deleting networking info but the tvs occasionally connecting back even though they deleted wifi info. You have to get a new network name to block them.
It's much much better to connect an external device, and if not that then use an ethernet cable to connect, because you can physically remove it.
Because the vast majority of people use whatever their tv came with these days in terms of smart tv connections, they don't set privacy settings. There's every reason for the tv makers to keep spying on you. If you have an external device their is motivation for them to not make you angry - but it's true that they can spy on you.
