Sure if this was my job, then I would do it but I am just contractor with set amount of hours devoted to the project. First few years was spend fighting fires as the company needed this very specific software to function, currently it is just about keeping eyes on having it run and occasional fix some report or update data pipelines.

I would say that rewrite would cost about 2 millions of euros. Which is really big price tag for company that use this system as a backoffice tool.