The BEAM virtual machine. Its has lightweight isolated processes, message passing, supervisors, hot-ish runtime introspection, and fault containment are not libraries bolted on later. They are the substrate. not an after thought.

if you are build an app that needs the following: + many concurrent users + real-time UI + background jobs + workflows + stateful sessions + distributed events + failure isolation + “this thing should keep running for months”

You're going to want the thing built on the BEAM.

Many people love liveview.

Many people dislike blazor and it has had its reputation sullied by Microsoft treating it as “new webforms” (yes, they do. It is literally the official migration path for legacy webforms projects).

The pro of blazor, arguably, is c# and the .Net ecosystem.

If I personally had to choose, I wouldn't choose blazor over almost any other technology because I’ve had bad experiences with it.

Technically, they're very similar, but the devexp matters, in my oppinion.

TLDR; LiveView is web only.

There have been efforts to make LiveView native, but it’s extremely difficult to do so, and thus far (to my knowledge) all have failed.

I was thinking about this the other day because carsandbids (Doug DeMuro’s car auction site) uses Blazor (at least as far as I can tell). And I think that’s one of its biggest advantages of Blazor—- is that it is capable of producing native apps and web apps while LiveView is resolutely not. And that’s because Microsoft can pay for it (or at least sponsor huge amounts of supporting infrastructure).

And FWIW— that’s an extremely difficult problem to solve. It requires an enormous amount of funding, both a huge team capable of both understanding Android and iOS SDKs and capital to employ folks on pure engineering challenges (hence why MS or Meta can). End users don’t care if it’s made with LiveView, Blazor, React, Java, SwiftUI, et. al. And, the list of companies that can facilitate that long term is extremely small.

There’s also the issue of OTP being non-trivial to implement or meaningfully transpile into another language/runtime. Erlang, BEAM, and OTP were made together for each other in a very peculiar and specific way, for a specific set of problems, and if it wasn’t a necessity that they were developed together it would be a dead language, runtime, and platform (and for the record it’s absolutely not).