No. It is not a universal remote. It will not control other apps on the TV, access TV menus, control other devices, etc.
I still use the LG remote when I need to access TV settings menus. Also when I tune local TV channels using the antenna instead of streaming with YouTube TV.
I’ve a family member with an AppleTV, and she really likes it. It has all the streaming apps for her services (Plex, Netflix, Amazon, etc). With AirPlay she can easily mirror her iPhone/iPad screen on the TV. I’ve used it when visiting. The system is fast and responsive. Since you use Apple products the user interface will be very familiar.
Strictly from a Plex point of view, the Shield Pro has advantages over the Apple TV.
The AppleTV cannot passthrough TrueHD or DTS audio formats (Apple restriction). The Plex Apple TV client also has problems with Dolby Digital Plus + Atmos (Plex problem).
The AppleTV does not passthrough TrueHD or DTS audio. This is an Apple restriction. Both are passed as PCM. The conversion is lossless, but any Atmos or DTS:X information is lost in the process.
The Plex AppleTV app also has issues with passthrough for Dolby Digital Plus + Atmos. In the Plex app, there are two underlying video players, the “old player” and the “new/enhanced player.” You can switch between them in the Plex app settings. As I understand things, the old player will passthrough DDP Atmos, but does not support HDR video. The new player supports HDR video, but does not passthrough DDP Atmos audio. Plex is aware of the issue and working on a resolution, but I’ve seen no information regarding progress, resolution dates, etc… For additional info, see Plex + ATV 4K 2022 Dolby Atmos (DD+) not working at all and EAC3 Atmos on Apple TV 4K does not appear to be passing through Atmos.
Many people use the Infuse app instead of the Plex app on the AppleTV. It has the same TrueHD/DTS restrictions as the Plex app, as those are imposed by Apple. The basic version is free. The Pro version costs money and adds support for Dolby Vision and Dolby Digital Plus Atmos passthrough. Their website has additional details.
