GraphQL vs Objective-C

1 code deploys for both: Android and iOS. There is a huge community behind React Native. And one of the best things is Expo. Expo uses React Native to make everything even more and more simple. Awesome technologies. Some other important thing is that while using React Native, you are reusing all JavaScript knowledge you have in your team. You can move easily a frontend dev to develop mobile applications.

A huge PRO of Expo, is that it includes a full building process. You run 1 line in the terminal, and 10 minutes after you have 2 builds done. Double check EAS Expo.

It purely depends on your app needs. Does it need to be scalable, do you have lots of features, OR it is a simple project with very simple needs - many of those parameters clarify which technologies will fit.

If you are looking for a quick solution, that reduces lot of development time, take a look at postgraphile (https://www.graphile.org/postgraphile/). You have to just define the schema and you get the entire graph-ql apis built for you and you can just focus on your frontend.

On frontend, React is good, but also need to remember that it is popular because it introduced one way data writes and in-built virtual dom + diffing to determine which dom to modify. Though personally I liked it, am recently more inclined to Svelte because its lightweightedness and absence of virtual dom and its simplicity compared to the huge ecosystem that React has surrounded itself with.

In all situations, frameworks keep changing over time. What is best today is not considered even good few years from now. What is important is to have the logic in a separate, clean manner void of too many framework related dependencies - that way you can switch one framework with another very easily.