[furi]

>Strong end-to-end encryption essentially means that the police cannot access communications ever, even if they get a warrant because they don't have a technical mean to do so.

This isn't true. It means they cannot access communications without revealing to at least one of the communicating parties that they are doing so. The messages are still decrypted on the endpoint devices for reading, a warrant could be used to acquire those devices from their owners. Device encryption can complicate this some of the time, but that remains fairly hit-and-miss (and is a separate issue, you could have mandatory key disclosure without backdoored E2E and vice versa).

>the police has always been able to access those communications should it be necessary and according to the law.

And neither is this. To find out the contents of a verbal conversation that was not recorded (most of them, even today) the police would need to ask one of the participants to tell them what happened, and the participants can usually refuse to self-incriminate. Even if the conversation was recorded the recording would usually be in the possession of one of the participants as recording a conversation while not being a participant is illegal, at least where I live. To find out the contents of a letter they would need to intercept it during transit or recover it from its destination at a later date. If the letter has been destroyed they're back to asking the recipient or sender to tell them what it said who again can usually refuse to testify. To find out what was said via instant messaging under this no end-to-end encryption scheme, they can, at any time, simply ask a third party who cannot refuse to testify. This is an utterly unprecedented invasion of privacy and I struggle to see anything that could justify it in a (part of the) world where crime seems to be on a downward trend.