It will be absolutely fine for Standard Dynamic Range content (SDR), It will be rubbish for HDR (High Dynamic Range) content. If you throw normal TV stuff at it like freeview HD channels, Blurays etc you will be fine. Just don't throw any HDR content at it.
The easiest way to do this would be to get a device like the Apple TV 4K and hard set it to SDR output only. This way you will still benefit from 4K resolution for all streaming services, but still get a really good SDR image.