My goal is to simply search the Apple App Store to know if a certain app name is already taken but without owning an iPhone/iPad or having an Apple developer account. Would that be possible, maybe there's a website that replicates the current state of the apple app store?
To answer my question, I've found this website: https://theappstore.org/
In the end though, the only way to know with 100% certainty that an app name is not already taken is to have an Apple developer account. This is because developers are allowed to reserve app names and even if the app name isn't currently on the app store, it doesn't mean its not already reserved by another developer.