I think you are only kind of right. aspx is over 10 years old, you should have switched to .NET MVC already and then the difference to .NET Core is small. We re

I think you are only kind of right. aspx is over 10 years old, you should have switched to .NET MVC already and then the difference to .NET Core is small. We rewrote some things at an earlier company and there mostly general things like auth and where to get querystring variables and similar that had changed. If we look at WCF to REST (or gRPC) it is also mainly easy since it is some general configurations and infrastructure things that have changed but most of the business logic will work. So you have to rewrite but it might be quite easy. And doing this once every decade is not that strange. Also remember that most of the old things still work. You can stay on those tech stacks for another couple of years if you feel that is better for your organization.