[up2isomorphism]

The fundamental question is that if an address is “safe” is a runtime thing, which in some cases you can decide it in compile time but not always. To force that during coding is just handicapping oneself to be “safe”. Which you can do the same in C (or mostly any language if you want it)

[tialaramex]

The languages we're discussing here are high level - like C - and so they don't have addresses like the machine code, they have pointers. With pointers we're back to the compiler needing to know if they're valid - if you delay until runtime you lose not safety but performance before the compiler optimises based on knowing whether values can be modified via a pointer and if that's only decided at runtime we cannot perform these optimisations so now our program is slower or bigger or both.