getFiles() not acting like an array

I am having an odd issue with the getFiles() function: It is returning the list of folders I want, but won't let me interact with them as an array.

Here is my code:

const basePath = "C:/Users/O146962/OneDrive - Kaiser Permanente/Documents/GitHub/kp_pd_xml_automation";
const mainFolder = basePath + "/Indesign Automation POC";
const templateFolder = Folder(mainFolder + "/Templates");
const rgnTemplateFolders = templateFolder.getFiles("*_inddTemplates");
alert(rgnTemplateFolders.length());

Note that the const templateFolder is declared as a Folder object.

If I set the alert to

alert(rgnTemplateFolders);

 The script produces the following:

If I set the alert to:

alert(rgnTemplateFolders[1]);

I get:

BUT, if I set the alert to:

alert(rgnTemplateFolders.length());

I get:

I have been hunting through these forums and found the following posts, but none of them seem to specifically deal with this issue.

• looping-thru-getfiles-array 
• Use getFiles() in an array
• Problem with getFiles()

What am I missing here?