Chromecast for KEY2 LE?

I was going to buy a Chromecast Ultra so that I can watch pictures and videos from my new KEY2 LE on my 4K Samsung TV, but as I was playing with my settings I discovered there is a Cast feature built into the phone already. Is there any benefit to getting the Chromecast Ultra or is it redundant? I appreciate any comments!

It's redundant. So long as you have the bandwidth over your router, you'll be able to cast fine directly to your TV

Thanks for taking the time to reply. We have fibre optic internet with a download speed of 100Mbs so should be fine with the built-in cast.