Before the pandemic I would've suggested raspi & the official raspi display. But those are damn expensive. The second option would be any cheapo Android tablet

Before the pandemic I would've suggested raspi & the official raspi display. But those are damn expensive. The second option would be any cheapo Android tablet + Kiosk browser. It lets you have any web page visible and the screen turns on at voice/motion. Or a more ready-made option would be an Elgato Stream Deck. You can customise the buttons pretty well.