> the data costs associated with the spying would be so great

I've just checked my monthly Discord traffic and it's mere 251MiB in/73MiB out. For roughly an 1-2 hours of gaming every other evening, and some longer weekend sessions.

Power usage, on the other hand, is a different story. When I've experimented with an app that'd continuously record everything around me, battery ran out in just a few hours.