• Miracast, from the Wi-Fi Alliance, an open and free standard that works reliably, without a need to even have a local Wi-Fi network, despite being developed by an organization who's entire purpose is to promote Wi-Fi equipment

• Google Cast, a proprietary protocol from Google, requires a common access point connection to share a screen, and it often takes multiple attempts, for it to load a shared screen before it times out

• AirPlay, a proprietary protocol from Apple, also requires a common access point connection to share a screen, but at least it loads reliably

Miracast is probably the most supported by TVs, but Apple doesn't include it on their phones, and while many Android phone manufacturers do include support, Google doesn't on their Pixel phones. Because of that, it's likely the least used of the three, despite being the best.

I hope Google Cast will be better.