VPN (and tor) users are the ones you'd be most interested in as a government. So it doesn't matter how much of the general population uses your VPN as long as y

VPN (and tor) users are the ones you'd be most interested in as a government. So it doesn't matter how much of the general population uses your VPN as long as you convince the ones you're interested in to use one. And for all of those not using a VPN, just ask the ISPs.