Of course, the real cost-saving is in labour—web development presents a radically lower barrier to entry compared to even non-native, cross-platform UI/UX platforms such as Qt, or Flutter, or what-have-you, let alone simply managing multiple native applications.
So this is not a bill-of-materials kind of analogy, it's a statement about talent.
Web leaders have grown complacent; at times, it seems they don't take things seriously. I mean, just take a look at something like SvelteKit. I'm not a web developer, however I happen to like Svelte a lot, but also despise SvelteKit equally as much.
Every major release is like "fuck you."