Hi I can't help you control TV with the pixel phone but if you have something like sky you can download an app that includes control of the sky, if you have Xbox you can download Xbox glass that's why not so many phones use if, if is dying and it would be dead already if they didn't use it in TV remotes.
I have a Logitech (Harmony) hub, I use my Pixel to control the hub, and the hub has an IR blaster. I can also turn on the TV, adjust the amp volume, change channels, etc. from work. Really messes with my gf.