Route does not appear when I select Find (button) > Routes.

I don't know...you're not the first person with this type of issue. I only use Tracks, so I don't pay much attention to Routes or Courses. But I recall them showing up under the Find menu. Now, they only show up in the Main menu. 

Indeed, well I'm still trying to get my head around the device's 'logic' (or the lack thereof), but so far I'm getting there and  I quite like it.

This is my view of the logic...Garmin bought a company called Delorme which had the Explorer....GPS plus inReach. Garmin made some improvements. More recently, across many devices, they appear to be incorporating across product lines. For example, the Route Planner is from their automotive GPS software. The Course Planner is from their fitness watch GPS software.

If you realize where some of these functions originate from, it makes it easier to understand.

Note that the Routes and Courses options in the Find menu will only show up if you actually have Routes and/or Courses on the device.

The Course Planner and Route Planner in the main menu are always shown when you have added them to the Main Menu (Setup > Menus > Main Menu).

Ok, thanks.  That cleared that issue up.

Yep, I was wondering why there are so many different planning & routing websites to sign up to, interrogate, link by Bluetooth etc., makes it a little more confusing but I'm understanding the reason why now?

IMO, the main benefit to crowd-sourced web sites (such as AllTrails) is the availability of boots-on-the-ground tracks. Even if the the cartography on your device has trails, the maps tend to be less than accurate.