People often are under the severe misconception that it costs less to buy a TV without features that 90%+ of the market wants. They are incredibly wrong. Like back in the days when 3D was super popular, people who didn't want 3D wanted TVs that didn't include this feature.
Don't be ridiculous. TVs have smart features built in. It doesn't make them better, or worse. Just get the best TV for your budget and hook whatever you want up to it.
I actually own a Roku TV that I never use the internal Roku with. Why? Because it is hooked up to my whole house distribution system which already has a Roku and I use the better speakers in my room while viewing. It didn't cost more to get it with Roku built in and your TV will not cost more for having integrated smart functionality.
Just get what your budget affords you and know it is the best TV. Ask questions relevant to buying the best image and quality, and ignore the smart features as they are irrelevant to your setup.