> AFAICT the point of arrays as a data structure is to allow relatively cheap indexing at the cost of more expensive resizing operations. What else would you do with an array other than index into it?

The main thing you do with arrays is bulk operations (e.g. multiply it by something), which doesn't require indexing into it. But yeah I think they're a fairly niche datastructure that shouldn't be privileged the way certain languages do.

> How is this not indexing with a little abstraction? Aren't slices just a way of packaging an array with a length field it a standard way?

Sure (well, offset and length rather than just a length) but the abstraction is safe whereas directly indexing into the array isn't.