By the time they do get big enough to hire internal IT, the Rube Goldberg system is entrenched. Then by the time they get big enough again to need an internal dev team because off the shelf SaaS no longer cuts it, it’s too late. It’d take too many dev resources too much time and money to fix the spreadsheets, design databases, and start popping out web apps.

Plus the software development process is too rigid for how fast business requirements can change. The accounting department will just do it in Excel in an afternoon instead of being willing to wait 2+ weeks for the next sprint.

So we end up at a place in big enterprises where only some things get successfully moved to something more robust but there just isn’t enough resources (or will to allocate those resources) to tackle every spreadsheet, and so there are always key parts of the business that will forever run on Excel.