It's really easy to get started with almost any language, the problem is becoming an expert in it. How can somebody become an expert on the nuances of JS, Typescript, Dart, etc not to mention libraries and APIs of each? And that's just for the frontend.
FWIW, I was able to write two small but useful program in Dart in one day, without any experience with the language at all:
- A script to convert CSV file to SELECT ... UNION ALL SELECT ... statements
- A script to parse my timesheet (in Emacs' org-mode) & insert it into my client's timesheet database
I just used these 3 resources:
[1] Dart language tour https://www.dartlang.org/guides/language
[2] Standard library introduction https://www.dartlang.org/guides/libraries
[3] Standard library reference (like JavaDocs) https://api.dartlang.org/stable/1.24.2/index.html
[4] And the pub package manager https://www.dartlang.org/tools/pub