Revanced is just an app with no special permission. It's not a firmware. It's open source. It can only patch an apk which you provide to it with standard android file-picker APIs.
From a security standpoint, can you tell me what's different about this vs "I ran this chunk of PowerShell that said it would patch Office to bypass activation"? After all, it's just a patch.
From a security standpoint, What's the difference between using revanced's open source patches and downloading literally any open source software from GitHub?