This is a question I get on virtually every training course I run.
Is Scrum the right approach for every problem?
No.
So, when is Scrum the right approach and when isn't it?
For me it comes down to 3 things...
1. The complexity of the product or service you're trying to build
2. Whether you'll need to respond to change (both changing requirements and change in the wider world)
3. The culture of your team and your organisation