Why are academics so reluctant to try out the latest apps in their work?

Why are you using TeXmacs when the vastly superior https://www.overleaf.com/ is available?

Any claim that something different is better have to be substantiated.

People know how to do write macros, automatically generate documents and do all sorts of things with LaTeX. Amazingly TeX even kerns properly which I can’t say for Adobe Illustrator never mind Microsoft Office.

You find plenty of people who think LibreOffice is OK, they might even convince a German state to try it. Later we will here they switched back to Microsoft Office because LibreOffice is not OK.

It's a distraction. The existing tool works good enough, and they have other more important things to do than learn a new tool.