ApplicationIntent=READONLY Question

I am just trying to make sure I understand the purpose of the Read-Only Routing list.

We are using ApplicationIntent=READONLY to read from secondary replicas.

In some of our Availability Groups we have only one Replica. In this case is there any point to having a Read-Only Routing List?

We have some cases where we have 2 replicas in the Availability Group. Does that mean in this case with ApplicationIntent=READONLY if there is no Read-Only Routing List, SQL Server will pick one of the replicas arbitrarily? And then setting up a Read-Only Routing List would be for designating which of the 2 replicas should be used?

Thankyou

It will follow the same order as it is displays in your AG properties window.