Every mobile project starts with the same argument, and it is almost always argued on the wrong terms. Framework benchmarks are interesting; they are rarely decisive. The decision is made by product characteristics, team composition, release cadence and the cost of being wrong.
Start with device capability. If the product depends on the camera pipeline, background location, Bluetooth peripherals or platform-specific widgets, native gives you a shorter path to the behaviour users expect. If the product is fundamentally content, forms and transactions, cross-platform closes that gap almost entirely.
Then look at your team. A single codebase maintained by four engineers usually beats two codebases maintained by two. The organisational argument outweighs the technical one more often than engineers like to admit.
Finally, price the reversal. Moving from cross-platform to native later is expensive but survivable. Discovering in month nine that your chosen approach cannot support a core feature is not. Write the decision down, with the assumptions, and revisit it at the first milestone.