I have worked on large and small projects with both in-house and outsourced teams. Each time, a host of variables impacted the "correct" decision.
That said, I think it would be hard to answer this question without having a better understanding of what the app is, the delta between the MVP and the vision, your ability to document / communicate your goals (functional or otherwise) to an outsourced team, how you define "better," etc.
In short, it depends.
P.S. Love reviewing apps and would be happy to beta test / provide feedback if you're willing to share. https://clarity.fm/toddlevy (First time's free.)