A perfect place for multimodal Assistent would be in Operating System's GUI. So that it sees and hears the same as its human user.
Just because we can doesn’t mean we should.
We're way beyond the days when every program you run has equal access to all your data. These days, different programs have different levels of data access.
https://www.zdnet.com/article/ethical-hacker-says-his-window...
You're basically exporting surveillance as an externality with recording technologies that by design collect everything around them. These technologies were basically multi-modal keyloggers.