If you want to get creative, you could create a custom dashboard and put an old iPod touch/Android device in kiosk mode and use it as a remote touch panel control for your home theater (or anything else in HomeAssistant).
I have two Lenovo M8 tablets ($100/each) that I'm using as home control panels - super convenient and rock solid. https://imgur.com/a/f0aNTRq
If you go this route, definitely buy the Android app FullyKiosk. It will let you lock the tablet to the HomeAssistant dashboard, automatically recover if something crashes, etc. I have it set up to use the built-in camera & motion sensor to automatically turn on the display if someone walks up to it or touches the tablet, and automatically turns the screen off after a few minutes of no motion.
> I've got an msi desktop gaming PC, an LG CX OLED TV, and a Yamaha RX-A2A receiver and they never played well together. The kids always had a hard time getting them all on at once and set to the right inputs and launching steam.
> So I created a Home Assistant automation that does all that, bought a Zwave button that sits on the coffee table, and now they just turn it all on with one button like it's a video game console.
I also plan to add "scenes" where I can just tap the button and the lights dim, and the media center gets put into movie mode, as well as a "music" scene for when I have parties, which would join the two zones my receiver supports an then start playing a playlist from spotify.