When Node Js is taught people often teach Express framework. If someone teaches AdonisJs, it will have similar effect on audience as mentioned above.
As a side point though, it is much less mature than rails.
Just going off the age, and number of: commits/releases/contributors.
Its GitHub pulse is also obviously not as “rapid”
Rails also has a rich set of libraries in the form of gems - which AdonisJs most likely doesn’t rival
Rails is also used/has been used in production by some major companies. Perhaps AdonisJs has been too, but it can’t be as many
Nest has a bit more mindshare right now - with Triplebyte, etc using them
The good part is that it uses Express under the hood (which probably is ending up becoming the Rack of JavaScript middleware) ...so you get the third party ecosystem compatibility.