I spent the past 2 years working in AutoCAD and was surprised to find that it really hasn't changed much in the past 20+ years, other than some simple UI change

I spent the past 2 years working in AutoCAD and was surprised to find that it really hasn't changed much in the past 20+ years, other than some simple UI changes. I ported over 100,000+ lines of Lisp from the mid 90s and it worked almost without modification though I did rewrite it for other reasons. That project has come to an end prematurely. Is there a real future in CAD programming? I feel like I've wasted a good chunk of my life on a dead language in a dead product. Is any of this knowledge portable?