While many models do work with HID keyboards and the Logitech k400, it starts to fall apart pretty quickly as you find apps may or may not support keyboards. It's very hard on most to understand that Samsung did not write for example the YouTube app and has little leverage to get Google to fix it.

This is no PC. Not even close. As to the phone app, the app seems to come and go out and in of favor.

What's so smart about these smart TVs is a good question. But the smart TV has a glaring issue. Folk want it to work as good as say a PC and keyboard. Forget about apps and browsers for a moment. But we're not there yet.

Advice? Turn off the smart TV (smart hub) and use other boxes to get it smarter. Besides Smart Hub is not about you. (what you say?) It's all about content and advertising delivery. Samsung has never hid that fact.
Bob