Security concern

Can the police or government access a passcode protected iPhone XS Max ?

A friend of mine had his phone seized thankfully nothinf was serious but this led me to ask myself are iphones really secure? I researched and found out that softwares and devices of cellabrite and graykey claim they can access the data on an IPhone XS Max and use Brute Force an IPhone XS max to try many passcodes and unlock the iPhone XS Max. This has led me to be concerned for everyones privacy. I want to know if its true that the police or government can access a passcode protected iPhone XS Max and extract its data. Please answer and explain with reasoning. Appreciate it. Thanks