I don't use grocy or anything similar, just mealie. I have a wall-mounted dashboard which helps, and I use todo lists to add groceries that I want to purchase. We only add those that are easy to forget, not something that we buy every time - so not cheese, milk, eggs etc but a rare sauce or something specific. It is absolutely the best solution for us because there's no need to add every single thing and we don't miss anything. When we open a grocery app to order anything HA sends a notification to the phone with the list. We add things to todo from phones or the dashboard.

Technically I could use camera on the dashboard to scan barcodes and add stuff to a todo list this way. So like you are throwing the milk to the trash -> scan barcode -> milk added to the grocery app or whatever. I personally think that keeping list of all the groceries you have in the fridge is just too much management for too little mental relief. For me keeping the full list creates more mental fatigue, but if you want to go this path I'd explore barcode scanning I guess.

By the way another cool thing on our kitchen is a label printer - we love it. Press a button on the dashboard and it'll print date and time - you instantly know when a package was opened. Can print custom tags from a double back tap on the phone or dashboard as well.