The commenter says about most apps. The use case you mentioned requires computing resources.
You can do the whole thing on browser too but it is not efficient way .
But in the case of delivery apps, finance apps, you don't need much compute as can work exclusively with APIs .
>>scbzzz+(OP)
Performance is likely not a reason anymore - and if it is, then it is the platform that imposes it (rust was runs fairly fast in a browser).