If you ever talk with an insurance guy or system admin, you will understand why as/400 can’t be replaced that easily and most of the time people were unhappy with generic stuff replacing it.

Once while the split of IBM was on table, Microsoft was only interested in AS400 line. They used to do a lot of critical things on them. Yes, even Microsoft.

One can emulate AS400 since the entire thing including hardware and OS is a virtual platform from the start. I am not into financial/insurance/travel so I didn’t investigate if IBM offers a POWER or Xeon replacement. You won’t be able to explain throwing away millions of lines working code to move to some current fashion framework/language. These people make their money from 1/1000s of cents.