SCOOP: Apple says it's not aware of anyone using Lockdown Mode getting hacked with spyware, on all kinds of devices.
There have already been a couple of documented cases of Lockdown Mode stopping spyware attacks. And there's been one case where an advanced hacking toolkit was designed to bail out if it detected Lockdown Mode on the target device.
If you're worried about spyware, you should use turn this security feature on.

Apple says no one using Lockdown Mode has been hacked with spyware | TechCrunch
The tech giant's claim that it has not seen any successful spyware attacks targeting Apple devices with Lockdown Mode enabled comes amid a leak of hacking tools targeting users running devices with older software.
