For me the reason I want a non-smart TV is the software is complete shit and even a Raspberry Pi runs smoother, and I can replace or upgrade the Pi when it becomes too old to be useful instead of the whole TV.
Those will all become dumb TVs over time, and then you're stuck using the crappy software to get to your HDMI input through all the lag even though the software is literally useless.
At least old TVs had ugly as hell but snappy and responsive menus. No waiting 5+ seconds between button presses because the home screen is lagging loading all those ads.
I caved in and got one anyway and I regret it. Manufactured e-waste. The amount of times I have to reboot the damn thing because even my HDMI input starts glitching out is plainly ridiculous.