I use and like Roku. It covers all the streaming services I’m interested in (Netflix, Amazon Prime, Now TV, BBC iPlayer, ITV Hub, All4, My 5).This isn’t the case for Fire TV, Apple TV, Android TV, or Chromecast which each lack at least one of these services. I also like that it’s independent of the big tech companies so less likely to get caught up in wranglings between them.
You can’t Chromecast to it. You can cast a few apps which include support for the DIAL casting protocol. This notably includes YouTube and Netflix. But you can’t cast apps which only support Google’s proprietary Chromecast protocol, which means you can’t cast most cast-enabled apps to it