Session aims to provide anonymity, Signal aims to provide privacy.
Yeah if you compare that with Facebook messenger and other such services but if you want secure communication it's not reasonable.
It's worth mentioning that Session had started out as a fork of signal.
In many jurisdictions, telecoms form an abusive oligopoly, and you need to provide a state-issued identity document to get a phone number.
That is not at all reasonable for normal usage - unlike well-known non-abusive authentication methods, such as a keypair; or its even simpler cousin, the username/password.
On top of that so many other things just inherently expect one to have a phone number. It would be somewhat odd to not have a phone number for most of the people I know and talk to through platforms like Signal.
So to your question of which is easier, having the state ID and a phone number is easier because I'll already have that for a multitude of reasons.
If you live in a place where its rare to have a phone number, then yes I agree Signal probably isn't a good choice.
Obviously, I'm not really claiming that it's not possible people are experiencing this issue, but it can't possibly be widespread.
I feel like most likely people are using android skins that aggressively kill apps in the background.
There's something deeply wrong with the way signal delivers messages...
For this reason, it's hard to trust them. The encryption quality is irrelevant if the slop coded client is blasting random photos to random contacts.
Send a GIF to Contact A, Contact B receives random private images? Absolutely inexcusable slop code project. This class of state management bugs should not be possible with a well-architected client, period.
Signal's E2E encryption is more like End 2 Random End.