Restricting the government via laws... The government implements the laws. Trying to restrict the government via laws is mostly just asking "pretty-please don't screw us over." They're not going to make a difference to a corrupt government. Government corruption will become more enticing too because of the added concentration of power it would have. How have laws been working for restricting Trump? He's shown how easily they can be sidestepped and manipulated.
Also, back then implementing end-to-end encryption of all calls wasn't feasible. That would have been the preferred option. It's feasible now. We have it. Why rely on something as fallible as government-restricting laws when we have better options?
It's better for power to be decentralized, as it is with every device owner having sole access to their own devices. As well as being able to communicate anonymously, which is huge for matters of free-speech and democracy.