Yep. I did this after my Android TV remote vanished into the couch dimension, and the phone route worked fine.
If you’re on iPhone, TVRem is one option I tried for controlling an Android TV from a phone. It handled the usual stuff, moving around menus, volume, play and pause, and typing with the phone keyboard. Typing search terms on glass is still faster than pecking through an on screen alphabet with arrow keys. Setup took me about a minute once both devices were on the same Wi Fi.
Product page and video:
On Android, I’d start with the Google TV app. It already includes a remote mode for Android TV and Google TV boxes and TVs. When I used it, pairing was simple, and voice search plus keyboard input saved a lot of time. It tends to work across most mainstream Android TV setups without much fiddling.
One thing tripped me up once. Your phone and the TV need to be on the same Wi Fi network. If one device is on guest Wi Fi or mobile data, the TV usually won’t show up in the device list.
I ended up sticking with the phone remote more than I expected. It’s handy when the original remote is dead, missing, or makes text entry feel slow and dumb. If you search a lot in YouTube, Plex, or streaming apps, the phone keyboard alone makes it worth doing.