You realize a Chromecast
requires a compatible device to operate, right? vs

TV is able to function independently? The latter means I don't have to give the kids a tablet/phone to watch something, that I can start something with (or even without!) my phone/tablet and then
leave the house with it without interrupting others watching (or having to find & transition to another device), I don't have to take a device from a kid playing a game on it just so I can watch something, etc. Yes, the former can work around these (to some degree, maybe), but considering I'm just getting
one of them to plug into a thousand dollars' or so worth of A/V equipment, $99 isn't going to induce heartburn.