Yes.
> Do languages need to grow in this way?
Yes.
> The overriding virtue of C is simplicity.
C is not simple. It used to be, but it's not been for a long time.
No.
> Do languages need to grow in this way?
No.
> The overriding virtue of C is simplicity.
It's no longer simple, especially not with the C11 memory model (which got retrofitted from C++11, and is totally incomprehensible without reading multiple hundreds of pages of PhD dissertations); however, gratuitously complicating C shouldn't be done.
I agree that a feature like this could be useful, but then there are other useful features which should be added too. Where do you stop? I hope the C standards committee does not succumb to the feature bloat trend we see in many other languages (hand on heart: how many people fully understand/master all of C++/23's features?).
Need proper arrays instead of pointers to contiguous parts of memory which are interpreted as arrays? Proper strings (with unicode)? Etc. - use a different language suitable for the job.
We really need to let go of the notion that complex software must be written in a single language. Use C for the low level stuff where you do not need/want an assembler or where you want full control. For everything else there are more suitable tools.
Do languages need to grow in this way?
The overriding virtue of C is simplicity.