Come to think of it, I should write up the techniques I use, too...e.g. I have simple wrappers around querySelector() and createElement() with a bit of TypeScript gymnastics in a JSDoc annotation to add intellisense + type checking for custom elements.
Would you be open to a pull request with a page on static analysis/type checking for vanilla JS? (intro to JSDoc, useful patterns for custom elements, etc.) If not, that's totally OK, but I figure it could be interesting to readers of the site.
And agreed on vanilla/dependency-free not being a silver bullet. There aren't really one-size-fits-all solutions in software, but I've found a vanilla approach (and then adding dependencies only if/when necessary) tends to help the software evolve in a natural way and stay simple where possible.