My LG OLED TV can be configured to load directly into a HDMI input. I keep it disconnected from wifi at all times. I never see the smartTV OS. It’s probably the best option because OLED panels are the best current display technology.
I use an AppleTV as an external media box for all my needs. But the same would apply for an Android box or HTPC setup etc.
AppleTV is the media box to use if you hate ads and value your privacy. Its Home Screen is just a grid of apps. No ads. None. It’s also way faster (CPU speed) compared to the competition.
Replacing a smart TV OS with a device made by Google or Amazon defeats the purpose. You’re still going to get ads plastered all over your Home Screen. And they still lag and stutter unless you pay a premium price for an 5 year old Nvidia shield. Either use an AppleTV or build your own HTPC.