So the cost is less the cost of "switching" and more the cost of initially writing a native app.
In turn the actual question is how to reuse as much code as possible between the web-app and native apps without it introducing a lot of friction.
And one of the few reliable, nicely (developer) usable answers for this is currently electron.
For "business logic" there somewhat are already other answers, some languages run on most targets reliable and there is also wasm which often still needs a bit more tooling but has a lot of potential for such use cases (e.g. see Disney which AFIK does have their core business logic compiled to a wasm blob and then "only" provide UI/system glue to bundle it in on all platforms their streaming app runs on).
The problem is UI, you really don't want to reimplement UI and the mapping of non HTML/CSS producing UI to a mix of HTML/CSS on some platforms and native components on other often doesn't work grate so it's not surprising people decided to "just go with HTML/CSS everywhere". And if you are already there going with electron isn't "that" much more overhead.
This is not specific to Electron, it's a similar effect with every core technology, all the way to COBOL.