When you're a large company, with literally 100s of 500K+ LOC apps around, you don't get to just rewrite them. That's the reality of a lot of enterprise shops and completely changes the perspective when looking at a codebase with various vintage technologies.

Sure you get to re-write them, and you are a fool not to. However the rewrite needs to be spread out over 30 years. Note that after 10 years your replacement needs to be rewritten as well.

The trick is figuring out what this the priority. There is some 40 year old software that mostly work: it runs fast enough; it doesn't have many bugs; it doesn't follow best practices that the software world has discovered since; and it rarely needs new features. This code needs to be rewritten but the value just isn't there. There is other code that at only 5 years old needs to be rewritten: it is full of bugs, new features have been tacked onto an architecture that wasn't designed to support it - this software needs to have a large budget given to fixing it in the long run this will save a lot of money. Most projects are somewhere in between, you should give the team a little extra time/budget so that they can keep the maintenance up to do and it will never get much worse.

I want windows 10 on ARM because I want a full windows OS on a phone that I can attach a monitor, keyboard and mouse to and run Visual Studio for development. I would also take a Linux phone that did this and run VS Code