The reasons for that are performance. So that one doesn't have to assume everything aliases everything else. It could be more clear though, like having explicit alias qualifier which would make it alias all and by default nothing aliases, or vice versa. Right now there is no easy way to make two unrelated types alias, one has to go via char* or use unions.

You can cast void* to something else and it will work, but you can't expect to get a random void* and presume it has some valid well defined data for you to read. You must know where it came from and what's been done to it.

As a rule of thumb if you just write dumb bytes it's char*. If it's anything else you must know what you're doing and there are ways to perform type punning that's within the spec.