Waze was the obvious acquisition, because the Map editor is well done and accessible on the web, the community is very active and Apple even used their data, but Google was smarter and acquired them.

Apple Maps is limited to Macs and iDevices, while Google Maps is accessible essentially everywhere (web and Search page and Android/iOS). Because of this, it's easier for the masses to update information on Google Maps than Apple Maps.

Though I'd give anything to be able to use Google Maps with CarPlay.

I honestly think Apple maps will always stay just "good enough" and that they have no current intentions on furthering it as a product.

Exactly. It works as a default included app and a tick on the features list. If better maps are worth it to you many options are available in the store, it doesn't hurt apple either way.

The answer is simple. Actually work on it. Not an easy answer, as this is surely incredibly difficult work.

Another path would be to somehow engage community to help. But Apple doesn't have this modus operandi AFAIK.

They need to start collecting their own map data and have a system in place to be able to make updates quickly.

Garmin?

Last I checked, one of Garmin's key mapping data providers is Here Maps (formerly NavTeq). "Here" is owned by a consortium of companies (primarily VW, BMW & Daimler) and licenses its data to a number of companies. Apple can become another licensee.

For its massive cash hoards, I gotta say that Apple is neither strategic nor quick to the table with acquisitions.

Another option would be TomTom, Apple is using their data already.