This really does depend. Ther gold standard really does go to things like GrapheneOS (but that requires a Pixel). See the Mobile operating systems recommendation page.
It may be a more thorough approach to use a phone that was not purchased within your state (Belarus) and has the ability for you to install an operating system that can be verified externally.
The reason for this is you can’t know that everything has been truly uninstalled or what might lie elsewhere within the system partition.
If you don’t think you’re under any kind of targeted investigation it may make sense to import a phone that is unlikely to be tampered with, and install a custom ROM on that. Though be mindful that it is compatible with your telecommunication provider’s network.
Alternatively an iPhone is not a terrible choice, when it comes to privacy and security, despite being closed source. Apple makes it quite difficult to tamper with the hardware itself.
Both Apple and Google are unlikely to be friendly towards a state like Belarus when they’re persecuting people for local infractions not considered to be criminal by international law. Therefore it is probably better if you put trust in US based services or EU services that are operating within democratic countries with good standing in the privacy community.
An iPhone may also appear less extraordinary as it’s far more ubiquitous than a device running GrapheneOS or some other custom ROM. Ie. it’s worth considering what would happen if the police found this device in your possession. Would they consider a security or privacy distribution of Android to be suspicious? Would this raise more questions?
How much of your life needs to be on a device that is in your pocket? Amnesic operating systems like Tails have distinct advantages of there being no evidence remaining after usage. Anything you do want to keep can be encrypted on an external USB stick, or persistent volume. A USB thumb drive can be hidden physically easily.
Likely because they blocked the servers. They have a static IP addresses that do not change. Many countries which restrict citizen’s freedoms start by blocking those IP addresses of services which might allow for circumvention of state authority. If we consider China as an example, there are a number of blocking methods they use. Some of these methods could be:
- The government signing up to the services to discover the addresses
DPI and other network traffic fingerprinting technologies ie programs which monitor the network and decide whether network traffic is “encrypted” or not. If a lot of people use the same VPN provider then this will be really obvious.
For circumventing that people usually need specialized obfuscation tools, like Tor bridges combined with some of the pluggable transports run on private servers abroad that are only used by that person. Commonly in China v2ray is also used, though I have never personally used that.
You may also find this presentation interesting: Roger Dingledine - The Tor Censorship Arms Race The Next Chapter - DEF CON 27 Conference.
I haven’t used it myself personally, but it appears to be developed by Citizen Lab, which are fairly well respected in the privacy community.