For non-technical users, having one UI with all their streaming apps built-in is honestly a useful feature. The problem is all the other spying, hijacking, slowdowns, and other bullshit. But it's often a desirable feature for many users at its core.
For a technical user: the smarts often serve no point, we already have a streaming solution. Unfortunately, higher end TVs with OLED panels and the such come with "smarts" built-in. So the best you can do is ignore it and hope the firmware updates (that you install over USB because you don't trust it with a wifi connection) don't cause a ton of UI slowdown over time or otherwise cripple the TV. But if we could buy a dumb TV with the same features, we would.
For a technical user: the smarts often serve no point, we already have a streaming solution. Unfortunately, higher end TVs with OLED panels and the such come with "smarts" built-in. So the best you can do is ignore it and hope the firmware updates (that you install over USB because you don't trust it with a wifi connection) don't cause a ton of UI slowdown over time or otherwise cripple the TV. But if we could buy a dumb TV with the same features, we would.