Yeah they're mentions because it's being done in small niches (there's also Ruby/Haxe + many other transpile to JS languages), I just think they'll always lag behind the other popular and well supported contenders listed. I could be wrong but that's my impression after having worked on all of them which all provide decent development development experiences and end results - though they vary in strength amongst the different categories.
It may not have the popularity but it has a well resourced technical team behind its development resulting in the Dart VM being a highly tuned technically brilliant piece of engineering. It has great support for server scenarios like gRPC [1] which I'd imagine is a popular back-end for Flutter iOS/Android Apps which is my personal #1 pick atm for native cross-plat iOS/Android development.
I was an early adopter and saw promise in Dart based on the strength of its technical team (originally led by Lars Bak, Kasper Lund, Gilad Bracha, Bob Nystrom, etc) so invested a lot of time in developing a express-like web framework [2], Jade View Engine [3], Redis Client [4], JSON Client, etc. It had a nice/clean development experience, well-designed / fast libraries and APIs even back then, but abandoned it 6 years ago after going to work full-time on my own Startup and have been out of the loop of Dart VM/Server since then. Here's a short list of Dart web server frameworks I could find after a quick Google Search:
Looks like Aqueduct [6] is the most popular at 1.4k stars, though I'd expect Dart Server is not going to see a major uptick until Google commits to a major project initiative like they're doing with Flutter & Angular Dart. So it might only see traction as a Dart gRPC server which can still provide an end-to-end development experience with SPA development with Angular Dart / gRPC Web / gRPC Dart and Flutter / gRPC Dart which I'll also add after having gone through a comparison of gRPC clients in different languages [6], Dart has basically the nicest async development experience [7].
> Dart Server is not going to see a major uptick until Google commits to a major project initiative like they're doing with Flutter & Angular Dart.
That's one of the important points for me. Google's commitment to Dart is... well.. Google-ish.
The original intention as an alternative browser VM is done, most of the founding team left, and for years only the Google Ads team kept it alive.
The Flutter "happened" and Dart had its "Ruby on Rails" moment. Now it seems tied to Fuchsia, too. A popular Non-google project would seem good, otherwise the comparison to Swift seems more appropriate than Go.
With WASM being the new hot thing, I fully expect something Blazor-Ish to become quite popular in the Go world, and to be honest, once compiler output is going down, it's not that hard: the frontend stack is embarassingly shallow.
I actually liked what I saw of Dart and like Bob Nystrom's way of communicating (he responds, but isn't all out evangelizing like e.g. some people representing projects that start with "R").
So don't get me wrong, it's great to see some enthusiasm, and it actually brought me back to fiddle around with it a bit over the holidays. But I still believe that's more my "I liked my Palm Pre/WinPhone 10 better than Android/iOS" side than the one correctly reading trends...
(I'm a Perl developer ATM, I clearly don't know a thing about "resume-building")
Dart originally got me more interested for its server side because of how the actor model seems presumably at its core. There aren’t so many languages like that.
The frontend frameworks in Rust are surprisingly good, and I wouldn't be too surprised if this becomes a mainstream option at some point.
That said, I generally find there isn't all that much advantage to sharing a frontend and backend language.