I do search for definitions/usage examples in Italian. Thinking more about it, I think most of the frustration comes from the Treccani iOS app, which is very helpful because you have all of Treccani offline, but it hasn’t been updated in years and so it’s missing a lot of what you get on their website.

> The difference here is between an n problem and an n^2 problem (if the site expands and wants to accumulate definitions from each language/dialect to ~several supported major languages, for example).

Yeah; here it’s not an issue because I only search for Italian dictionaries, I voluntarily exclude any sort of Italian<->French/English/etc dictionary because I learn a lot more when I stay in one language instead of translating.

> (which I attribute to some of the words being in a dialect mostly spoken by older Italians who don't use the internet)

Yes. Even in the case of Neapolitan, which is still very active, it seems that all the studies of the language were done before the Web, and so you find a lot of good paper dictionaries in Naples, but pretty much nothing online. Most of the content is found on some random blog where someone listed 300 verbs in Neapolitan or an AltaVista page where someone wrote the meaning of a couple hundred words.