Its hard to find TVs that aren't smart, and I don't really see the point to limiting your choices to non-smart anyway. And we all know from how cheap Raspberry Pis are that it doesn't add that much cost to the TV.
I have a smart TV because that's the only way the OLEDs come. When the software on it gets obsolete I'll pull the ethernet cable out of it. Problem solved.
One thing I've noticed is that Youtube apps on TVs seem to limit themselves in terms of resolution. You can check by turning on "Stats for Nerds" on any Youtube app. My 1080p OLED won't play Youtube videos at a resolution higher than 720p30. Same with a Friend's samsung 4K, but a coworker's brand new 4K OLED will do 1080p60 but not 4k.
I know my TV's SoC will do 1080p because the Amazon Video app will do it.
So I do most of my Youtube via PC. The whole Smart TV thing is marginal. I have zero complaints about the Amazon app, though- its pretty much perfect.