2. Here are two nuanced arguments about each that I’ve seen:
Communications privacy is good in the small and mirrors the world with earlier technology with some differences. In the large it can allow maintaining much larger conspiracies than were previously possible with private meetings. One may consider it acceptable from a privacy and free speech perspective to allow secret communication in small groups but less secret communication in large groups. Indeed for political speech in a modern democracy you generally want it in public anyway, and WhatsApp and signal have small group sizes so you get this anyway. For very large groups, leaks seem hard to avoid. A counter argument might be that militaries / companies are in some sense like conspiracies in the way they want to keep state/trade secrets. However in typical democracies there may be document release schedules/transparency laws and internal company information may be revealed through patents, subpoenas, or just plain old leaks.
The money argument is that whereas people typically have similar amounts of private speech, some people have many orders of magnitude more money than others. Privacy for communication is then reasonably fairly distributed across the population (though those with more to hide may gain more) whereas privacy for money is mostly an advantage for the people with lots of it. Giving the people who are already rich and powerful this kind of advantage in avoiding scrutiny/taxes may not be considered fair or desirable. A counter argument could be that it is unfair for the rich to be exposed to such increased scrutiny merely because of their money.