Instead of looking for anti-authoritarian services to hide from authoritarian government services you should probably blend in with the fish like Mao said:
> The guerrilla must move amongst the people as a fish swims in the sea.
It's better to create false identities that are seemingly legit and fully fleshed out, for example: with back stories, and utilize regular services as a normal person would. The key is disconnecting your own identity from the false one. Rather than trusting your security to a 3rd party service that makes a name for themselves on helping people trying to hide their identity, thereby attracting scrutiny.
That being said there are ways to use encryption services in a way to protect your communication but the bar for doing so is very high and most people will either make mistakes or get lazy. Fortunately services like Whatsapp and to a lesser extant Signal are so popular that you could easily blend in using them, while still having high-quality data encryption. Although they both use phone phone numbers for authentication and the device itself is always a weak-link which is why the identity part is so critical.
thegrugq posted an article a long time ago about how CIA agents in Lebanon [1] got caught because they used burner phones in a way that was unlike the way anyone else used cell phones, if I remember correctly: they were turned off the device most of the time except to make a few calls to other phones that were similarly not used often - not in the way normal people make calls. So anyone in control of the mobile operators would be able to ID potential evasive behaviour an zero-in on those devices/people for extra scrutiny.
That type of behavioural analysis that applies to real life can even more easily give you away in the digital world. Which is why it's important to not stand out from the crowd by using services like Riseup when your entire goal is privacy.
[1] http://grugq.github.io/blog/2013/03/12/anonymity-is-hard/