Let's say your framework size is something wildly unrealistically ludicrous, say 10 MB after gzipping etc. Assuming daily deploys, with the average US internet connection being 18 Mbps, that's a wait time of about 4.4 seconds per user per day: Even in this nuclear unthinkable scenario of 10MB, the result to the end user is a 4 second wait time if they refresh right after your deploy, and then it's instant due to caching. This is a noticeable, minor annoyance to the user but nothing to lose sleep over. Your app can still be successful, as GMail has proven, which would probably take 10s to start even on a quantum computer.
Now let's bring those numbers down to the real world. We're choosing between a framework that's 20kb and one that's 50kb. 8 and 22 ms total user wait time per deploy respectively. Even on mobile, users will never know the difference.
Back to Scala.js. I love Scala, and I want to work with and hire people who love Scala. Using this language is of critical importance to my business. Why should I consider giving it up to save 14ms/user/day?
The framework is basically the entire Scala runtime. You need a list - you execute that code. Not a biggy
But if you're developing a larger front-end application, that tax is dwarfed by the size of your actual application.
Also, Scala.js can be and is used for other JS-based environemnts, which are less size-constrained, such as Node.js, electron, etc.
What do you think will be the long-term story for Scala.js, with WebAssembly becoming mainstream, and current WASM shortcommings (e.g. GC and concurrency) out of the way? Do you expect Scala.js folding back into Scala?
Other question, does Scala's moving towards DOT-based foundations (e.g. dotty) affect Scala.js?
Scala moving to DOT-based foundations is orthogonal to Scala.js. We'll have to rewrite parts of the compiler to adapt to dotty's internal, of course (and that is being done ), but at the language level, it is entirely orthogonal. Of course, we'll benefit from a better union type, which is very important for Scala.js, but it's not really a language interaction.
Not to mention no more misspellings of attributes with strong typed html