I think Fk constraints are still valid and a good thing to do. Like you mentioned, you changed something and they pop up. You define that there is a necessary

I think Fk constraints are still valid and a good thing to do. Like you mentioned, you changed something and they pop up. You define that there is a necessary relationship between certain things and define it once in your schema. Your sql server takes care of enforcing it. You don’t need to remember every time about this relationship. So there is one thing less you need to take care of/which can cause issues.