Money laundering is linked to criminal activity by definition. It literally means introducing the proceeds of criminal activity into the legitimate financial system.
I think that's a good general definition. But sometimes people want to move capital unlinked to crime across borders. They then use exactly the same mechanisms money launderers use. If you have a term for that you like better, I'd be interested to hear it.
If it's not the proceeds of crime, but just money leaving because of unfavourable domestic policies, it's normally called "capital flight" rather than money laundering.
That's only true if they are trying to avoid taxation, which is also ilegal (even if you think it is justified). Moving capital from a place to another doesn't use the same mechanisms of money laundering if done legally.
That's a good example that proves my point and the reason why I said "even if think it is justified", it doesn't matter if it is a cap/tax/whatever, it only uses the same mechanisms of money laundering because it is money laundering (they are trying to hide that that money is not clean/legal, that the reason it is illegal is because it was not supossed to legally leave the origin country instead of being drug money, makes no difference to the law, but morally could be ok to some).