Yeah, that was ~ 1 decade ago. I'm fully aware that you could have a modern web experience with Microsoft way back 10 years ago. But 10 years ago isn't today. Today is today, and Microsoft no longer provides a modern web experience.
AJAX isn't modern anymore. Don't you see that the AJAX innovation was a game changer, but that the game has moved on since then?
How soon we forget! There would be no AJAX today had Microsoft not introduced XMLHttpRequest to make Outlook Web Access work...