But in regards to my Kotlin question, I don't mean "what is your opinion of kotlin in general," I guess I mean more so relative for the situation's where it makes sense to use it, like android dev. Also in regards to Kotlin Native (
Kotlin/Native - Kotlin Programming Language) which apparently allows you to compile it cross platform not using the JVM, so for instance, does Kotlin make sense if I want to develop an app that works on android and iOS? etc.
Difficult question, so I'll try to elaborate a bit, which will probably sound rambling.
While there is a native LLVM backend for Kotlin you should be always aware that choosing a compiler/toolchain is always a matter of trust. Compilers these days are incredibly complex pieces of software, and you want something that is maintained and has earned the trust of many to generate correct code and optimize well without breaking things.
If you take configuration management serious (some industries have to) you have to version control not only your source and artefacts, but also your toolchain, operating system, and in hard cases your whole computer + CPUs. You have to validate everything affecting the outcome of your toolchain.
Also, keep in mind that when you choose a language/framework you essentially buy into its whole ecosystem. Do you need to interoperate with SQL databases, parse XML, drive OpenGL or talk to hardware devices on the USB bus or Bluetooth? Of course you can link to native libraries in most cases, but do you have to write bindings yourself, and are the libraries thread-aware/safe? Does your language automatically generate green threads or thread pools for async I/O and futures? Lots of questions to check out beforehand.
In the case of frameworks like React the basic promise is to let you quickly achieve results with an minimum amount of code and invested hours. Because manhours for developing/debugging/QA are the thing that drives software development costs. This fits the modern agile software development paradigm to ship as early as you have an auto-updater for your project, so you can push new releases to your customers.
The downside will always be that when a) things break you don't really know how stuff works under the hood, and b) if you want to do things not easily covered by your framework you are having to look around where to bolt things on to.
So, to come around: Yes, Kotlin is an OK choice if you want to develop an app that works on both Android and iOS. Its even ok to create something like a microservice in it for your larger architecture. OpenAPI can generate Kotlin. But if you want to scale your project you need to find programmers that either know the language and ecosystem, or are willing to learn it. Of course if I sit an C++ programmer on Kotlin soure he can write and debug programs somewhat after showing him the basics, but he will not use the features like channels well, or maybe stuck when debugging problems when he encounters code with features he is unfamiliar with.
These are all considerations you have to do on a case-by-case or project-by-project basis. If you work alone you can do whatever, if you build a team for a project from scratch you can look for experienced people, or people willing to learn. If you already have an established team and/or a legacy codebase you may be stuck.
