If I write a C program, especially with the appropriate compiler warnings enabled, or some filesystem code, there is a high chance that it will work across platforms with no further coding necessary. Anecdotally, the same cannot be said for CSS or SQL.
It doesn't matter much for SQL, because I always know what database I'm using, but for CSS, it's a massive pain.
That's a charming belief about C which is only true if you work on the same operating system, processor, and don't do anything complicated. If those are not true, as I've experienced many times over the years, you will learn otherwise about things like differences in floating point behaviour, memory allocation and access patterns, which filesystem and/or locking semantics, etc.
In other words, it's about as true as it is for CSS and SQL, where that kind of simple use is also stable.
Yes, I write fairly boring applications. But the point is that C is mostly cross-platform for those boring applications, whereas the the "cross-platformness" of CSS and SQL fall apart for even the simplest of tasks.
Again, I think you're viewing this through the lens of relative experience. I have seen tons of C code which required substantial fixes to work portably (bonus points when this was exploitable) and I have plenty of CSS and SQL which hasn't had to be touched in years.
I'm guessing you can get pretty far by compiling the chunks into meshes at multiple levels of detail (2x2, 4x4, 8x8, etc.), each with the same (or similar) number of vertices.
You can easily silence such a warning by writing `let _ = f(...)`, though, but I don't think that's a bad thing.