> Telegram does not publish server-side code

Given this, why should anyone trust Telegram over WhatsApp?

For the average person I don't see why you should use Telegram instead of WhatsApp if most other people are using the latter.

For journalist or activists, or anyone that might face persecution Signal is the only reasonable option. I guess you could make the argument people falling into that category stand out more unless Signal has lots of users?

And does that imply Signal will eventually have to find ways of monetization other than donations?