I don't think you appreciate the zeitgeist. People were building complex systems: compilers, operating systems, databases, numerical simulations, and worse in machines with less memory than an Arduino. Adding a byte to every string was widely viewed as madness.
Yes, of course. The only problem is that now my iPhone is more performant than top supercomputer was then, but this ugly hack with strings is still there, alive and kicking.
And even then — one byte of memory could be nothing compared to CPU overhead. Or maybe not — RAM was insanely expensive these days.
But you're comparing apples and pears. This 'ugly hack' is - for obvious reasons - not what 90% of software on your iPhone is actually using to manipulate strings. Instead, the ugly hack known as NSString tidily wraps the char buffer, its byte-length, possibly an offset - most application developers never deal with null-terminated strings!
So in other words, I don't really understand why you are arguing for replacing a standard - one that works well for its purposes, mind you - with another when this has in fact already happened. And even less I understand why you are trying to frame a good and sound engineering decision as somehow a mistake?
If the strings is under 255 characters, using Pascal strings have the same cost. You keep "wasting" a single byte for null character or an counter. Null terminated strings becomes more space efficient when you need to store longer strings.
