For example:

> function a() { console.log(a.arguments); }
undefined
> a(1)
Uncaught exception: 
[TypeError] Restricted function properties like 'callee', 'caller' and 'arguments' may not be accessed in strict mode
 -> <unknown>
 -> a
 -> <unknown>
 -> (global execution context)
>

Seen on: https://www.smashbros.com/wii/en_us/gamemode/wi-fi/wi-fi06.html
Also required by Closure library, which takes an arbitrary function as a parameter and extracts the arguments from it: https://github.com/google/closure-library/blob/1d34579ab3e18825017bd21f5b3a0e7636f5f4c1/closure/goog/debug/debug.js#L582

This is a non-standard feature that every major engine has and the web depends on. This would pretty much require removing the m_might_needs_argument_object optimization, for example in this extreme case:

> const blah = eval; function a() { console.log(blah("function d(smfn) { console.log(smfn['arg' + 'u' + 'ments']) } const c = a; d(c)")); }
undefined
> a(1)
Uncaught exception: 
[TypeError] Restricted function properties like 'callee', 'caller' and 'arguments' may not be accessed in strict mode
 -> <unknown>
 -> <unknown>
 -> a
 -> <unknown>
 -> (global execution context)