AngularJS select doesn't work without ng-model
Using the select tag within an Angular app generates the ng-select directive, which is an HTML SELECT element plus angular data-binding. Looking in the Angular source for this select directive, here are the first few lines from its link method:
link: function(scope, element, attr, ctrls) { // if ngModel is not defined, we don't need to do anything if (!ctrls[1]) return; ...So it is actually built into the framework to abort linking the directive if ngModel is not defined, and so no binding takes place.