What language/stack are you using? If you know, let me know, might be able to help.
If you don't, you don't know enough to be a technical hirer/boss in this situation.
If you don't, you don't know enough to be a technical hirer/boss in this situation.
It's hard enough for someone who does it professionally for years to know why they should pick Flutter over Native, or Vue over React. Most people probably can't afford the best stack anyway. Let the freelancer decide what's best to build the product in.
Outsourced work tends to be hacky and unmaintainable for the most part. Sometimes it's built cheap, with no architecture whatsoever or designed for a very specific situation. Even worse, it could be overengineered.