I’m going to assume that both you and the OP are engaging in this in good faith. I am thoroughly in the “legislating encryption is basically outlawing math” camp and believe it’ll be highly ineffective at accomplishing any of its goals. However…
Get a warrant for what exactly? On, say, an iPhone where you can have reasonably secured encryption-at-rest for your data (the entire disk is encrypted using an AES key that is protected by your passcode and that key is destroyed after too many failed attempts), simply getting a warrant to take physical possession of the device doesn’t really provide any evidentiary value. In the US and many other jurisdictions (but not the UK from what I recall), courts generally can’t compel someone to reveal their passcode. The E2E keys are stored encrypted at rest as well.
Get a warrant for what exactly? On, say, an iPhone where you can have reasonably secured encryption-at-rest for your data (the entire disk is encrypted using an AES key that is protected by your passcode and that key is destroyed after too many failed attempts), simply getting a warrant to take physical possession of the device doesn’t really provide any evidentiary value. In the US and many other jurisdictions (but not the UK from what I recall), courts generally can’t compel someone to reveal their passcode. The E2E keys are stored encrypted at rest as well.