Today while cleaning windows, came up to my mind how I miss when developers not only knew what is but also how to implement ajax requests properly....
Nowadays a framework with 10 composer packages will do the trick, and looks like black magic to juniors

Is it really a surprise? Who wants to use naked JS, CSS and HTML? All the millions of frameworks are the testimony to the mess that the modern web dev has evolved to due to the usage of the old tools for the new requirements of web apps.

Okay mr flex, tell me how to do a cross origin ajax request in IE8 without googeling.

I can do you one better: I remember in 1996 writing a webapp at work that was a single HTML file. When the user clicked a button, rather than asking the server to render a whole new page, I instead set the location of the document in a hidden frame to a single "API" URL on the server (just an ASP page) with a request parameter specifying the function to execute. The server generated a new document that was nothing but JavaScript containing data, and an onLoad handler that called a function in the parent document, passing it that data. That function then updated the existing DOM on-the-fly with the data. I remember showing my coworkers this and they couldn't believe what they were seeing. Microsoft wouldn't invent Outlook Web Access until 1998, and Jesse James Garrett wouldn't coin the phrase AJAX until 2005, but I in effect was using the same basic idea and implementing what we now called SPA's in 1996, and I'm certain I wasn't the only one. Too bad I didn't publish :(