Each brand has its pros and cons, it depends on what you are looking to get out of the device. I use Roku because it is compatible with most apps, including Spectrum, which is not always the case with Google devices. However, there are features that other brands have that Roku does not.
The newer Roku generation devices should be able to handle the content with your TV. Here are the adjustments you can make to help picture quality.
How to improve image quality using picture modes on your Roku TV system | Official Roku Support
